If you want to detect and respond to changes on one object, you'd use observables. If you want to detect and respond to changes of a collection of things, use an observableArray
. This is useful in many scenarios where you're displaying or editing multiple values and need repeated sections of UI to appear and disappear as items are added and removed.
In boxing, a knockout (KO) is when a boxer stays down for a count to 10 from the referee, at which point the boxer loses the match to his opponent. If the boxer manages to get up before the count of 10, he can continue the fight until he gets knocked down (KD'd) again.
Example
Knock out watch online hight quality video. A knockout is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, muay thai, mixed martial arts, karate, some forms of taekwondo and other sports involving striking, as well as fighting-based video games. A full knockout is considered any legal.
To see how you can bind the observableArray
to a UI and let the user modify it, see the simple list example.
Key point: An observableArray tracks which objects are in the array, not the state of those objects
Knockout Count Crossword Clue
Simply putting an object into an observableArray
doesn't make all of that object's properties themselves observable. Of course, you can make those properties observable if you wish, but that's an independent choice. An observableArray
just tracks which objects it holds, and notifies listeners when objects are added or removed.
Prepopulating an observableArray
If you want your observable array not to start empty, but to contain some initial items, pass those items as an array to the constructor. For example,
Reading information from an observableArray
Behind the scenes, an observableArray
is actually an observable whose value is an array (plus, observableArray
adds some additional features described below). So, you can get the underlying JavaScript array by invoking the observableArray
as a function with no parameters, just like any other observable. Then you can read information from that underlying array. For example, Guide to gambling.
Technically you can use any of the native JavaScript array functions to operate on that underlying array, but normally there's a better alternative. KO's observableArray
has equivalent functions of its own, and they're more useful because:
- They work on all targeted browsers. (For example, the native JavaScript
indexOf
function doesn't work on IE 8 or earlier, but KO'sindexOf
works everywhere.) - For functions that modify the contents of the array, such as
push
andsplice
, KO's methods automatically trigger the dependency tracking mechanism so that all registered listeners are notified of the change, and your UI is automatically updated which means there is a significant difference between using KO's methods (i.e.,observableArray.push(..)
) and JavaScript native array methods (i.e.,observableArray().push(..)
) as the latter don't send any notification to the array's subscribers that its content has changed.
The rest of this page describes observableArray
's functions for reading and writing array information.
indexOf
The indexOf
function returns the index of the first array item that equals your parameter. For example, myObservableArray.indexOf('Blah')
will return the zero-based index of the first array entry that equals Blah
, or the value -1
if no matching value was found.
slice
The slice
function is the observableArray
equivalent of the native JavaScript slice
function (i.e., it returns the entries of your array from a given start index up to a given end index). Calling myObservableArray.slice(..)
is equivalent to calling the same method on the underlying array (i.e., myObservableArray().slice(..)
).
Manipulating an observableArray
observableArray
exposes a familiar set of functions for modifying the contents of the array and notifying listeners.
pop, push, shift, unshift, reverse, sort, splice
All of these functions are equivalent to running the native JavaScript array functions on the underlying array, and then notifying listeners about the change:
push( value )
— Adds a new item to the end of array.pop()
— Removes the last value from the array and returns it.unshift( value )
— Inserts a new item at the beginning of the array.shift()
— Removes the first value from the array and returns it.reverse()
— Reverses the order of the array and returns theobservableArray
(not the underlying array).sort()
— Sorts the array contents and returns theobservableArray
. The default sort is alphabetical, but you can optionally pass a function to control how the array should be sorted. See the example undersorted
below.splice()
— Removes and returns a given number of elements starting from a given index. For example,myObservableArray.splice(1, 3)
removes three elements starting from index position 1 (i.e., the 2nd, 3rd, and 4th elements) and returns them as an array.
For more details about these observableArray
Casino match play meaning. functions, see the equivalent documentation of the standard JavaScript array functions.
sorted and reversed
sorted()
— Returns a sorted copy of the array. This is preferable tosort
if you want to leave the observable array in its original order but need to display it in a specific order.The default sort is alphabetical, but you can optionally pass a function to control how the array should be sorted. Your function should accept any two objects from the array and return a negative value if the first argument is smaller, a positive value is the second is smaller, or zero to treat them as equal. For example, to sort an array of ‘person' objects by last name, you could write:
reversed()
— Returns a reversed copy of the array.
replace, remove and removeAll
observableArray
adds some more useful methods that aren't found on JavaScript arrays by default:
replace( oldItem, newItem )
— Replaces the first value that equalsoldItem
withnewItem
.remove( someItem )
— Removes all values that equalsomeItem
and returns them as an array.remove( function (item) { return item.age < 18; } )
— Removes all values whoseage
property is less than 18, and returns them as an array.removeAll( ['Chad', 132, undefined] )
— Removes all values that equal'Chad'
,123
, orundefined
and returns them as an array.removeAll()
— Removes all values and returns them as an array.
destroy and destroyAll (Note: Usually relevant to Ruby on Rails developers only)
The destroy
and destroyAll
functions are mainly intended as a convenience for developers using Ruby on Rails:
destroy( someItem )
— Finds any objects in the array that equalsomeItem
and gives them a special property called_destroy
with valuetrue
.destroy( function (someItem) { return someItem.age < 18; } )
— Finds any objects in the array whoseage
property is less than 18, and gives those objects a special property called_destroy
with valuetrue
.destroyAll( ['Chad', 132, undefined] )
— Finds any objects in the array that equal'Chad'
,123
, orundefined
and gives them a special property called_destroy
with valuetrue
.destroyAll()
— Gives a special property called_destroy
with valuetrue
to all objects in the array.
So, what's this _destroy
thing all about? It's only really interesting to Rails developers. The convention in Rails is that, when you pass into an action a JSON object graph, the framework can automatically convert it to an ActiveRecord object graph and then save it to your database. It knows which of the objects are already in your database, and issues the correct INSERT or UPDATE statements. To tell the framework to DELETE a record, you just mark it with _destroy
set to true
.
When Knockout renders a foreach
binding with the parameter includeDestroyed: false
set, it will hide any objects marked with _destroy
equal to true
. So, you can have some kind of 'delete' button that invokes the destroy(someItem)
method on the array, and this will immediately cause the specified item to vanish from the visible UI. Later, when you submit the JSON object graph to Rails, that item will also be deleted from the database (while the other array items will be inserted or updated as usual).
Determining if a property is an observableArray
In some scenarios, it is useful to programmatically determine if you are dealing with an observableArray. Knockout provides a utility function, ko.isObservableArray
to help with this situation.
Delaying and/or suppressing change notifications
Normally, an observableArray
notifies its subscribers immediately, as soon as it's changed. But if an observableArray
is changed repeatedly or triggers expensive updates, you may get better performance by limiting or delaying change notifications. This is accomplished using the rateLimit
extender like this:
Tracking array changes
Knockout Countdown
Although you can subscribe to and access an observableArray
just like any other observable, Knockout also provides a super-fast method to find out how an observable array has changed (i.e., which items were just added, deleted, or moved). You subscribe to array changes as follows:
The main advantages of subscribing to changes:
Performance is
O(1)
in most cases, i.e., there's basically no performance implication at all, because for straightforward operations, (push
,splice
, etc.) Knockout supplies the change log without running any difference algorithm. Knockout only falls back on an algorithm if you've made an arbitrary change without using a typical array mutation function.The change log just gives you the items that actually changed.
Here are examples of how the changes are reported:
As shown above, the changes are reported as a list of added and deleted values. The indexes for deleted items refer to the original array, and the indexes for added items refer to the new array.
When items are re-ordered, as shown in the last example above, you will also get moved information. You can choose to ignore the moved information and just interpret it as the original Alpha
being deleted and a different Alpha
being added to the array's end. Or you can recognize that the moved information tells you that you can think of the added and deleted values being the same item that just changes position (by matching up the indexes).
An observableArray
has array tracking enabled at construction, but you can extend any other subscribable
(i.e. ko.observable
and ko.computed
) as follows:
Knockout Count Crossword
Knockout..
The easiest way to understand moneyline wagers is by using a $100 bet. Using the above example, the moneyline on the underdog Buccaneers was +136. At +136 odds, a $100 wager would pay $136 in profit if the Buccaneers won the game (for a total payout of $236). Bettors often like picking underdogs because they are usually 'plus' money. This side of the moneyline bet pays out more money per unit than a. A moneyline bet simply involves you picking one of two teams to win the game. No catch, no angle, just the right answer or the wrong answer. Each team/person in a matchup for a moneyline betting option is given a separate numerical value for bettors to wager on and these are called 'odds.'. Moneyline bets take the gold medal when it comes to simplicity. Pick a winner, decide if the payout you'll receive is worth the risk, make the bet, and that is it. If your team or player wins, you win. People will try and overcomplicate this, but that is all there is to it.
Смотреть что такое 'Knockout' в других словарях:
knockout — knockout→k.o … Das Wörterbuch der Synonyme
knockout — knock‧out [ˈnɒk aʊt ǁ ˈnɑːk ] noun [countable] an arrangement in which people who are trying to buy the same thing agree not to compete against each other on the price: • It appears to be doubtful whether a knockout was arranged. • a knockout… … Financial and business terms
knockout — knock out , knock out knock out , n. Act of knocking out, or state of being knocked out; the act of rendering a person unconscious by a blow. [WordNet sense 1] [Webster 1913 Suppl. + WordNet 1.5] 2. a blow which causes a person to become… … The Collaborative International Dictionary of English
knockout — [näk′out΄] adj. that knocks out: said of a blow, etc. n. 1. a knocking out or being knocked out 2. a) a blow that knocks out b) Boxing a victory won when the opponent is knocked out: cf. TECHNICAL KNOCKOUT ☆ 3. Slang a very attractive or striking … English World dictionary
knockout — Adj k. o … Etymologisches Wörterbuch der deutschen sprache
knockout — (n.) also knock out, in fighting, 1887, from verbal phrase knock out to stun by a blow for a 10 count in boxing, short for to knock out of time; see KNOCK (Cf. knock) (v.) + OUT (Cf. out). Slang meaning attractive person is from 1892. To knock… … Etymology dictionary
knockout — ► NOUN 1) an act of knocking someone out. 2) Brit. a tournament in which the loser in each round is eliminated. 3) informal an extremely attractive or impressive person or thing … English terms dictionary
Knockout — KO and K.O. redirect here. For other uses, see Ko (disambiguation). For other uses of knockout , see Knockout (disambiguation). A knockout can be characterized by temporary unconsciousness. A knockout (also referred to as a K.O.) is a fight… … Wikipedia
knockout — [[t]nɒ̱kaʊt[/t]] knockouts also knock out 1) N COUNT: also by N In boxing, a knockout is a situation in which a boxer wins the fight by making his opponent fall to the ground and be unable to stand up before the referee has counted to ten. 2) ADJ … English dictionary
knockout — knock|out1 [ˈnɔk aut US ˈna:k ] n 1.) when a ↑boxer hits his opponent so hard that he falls down and cannot get up again ▪ The fight ended in a knockout. 2.) informal someone or something that is very attractive or successful ▪ Her dress was a… … Dictionary of contemporary English
push( value )
— Adds a new item to the end of array.pop()
— Removes the last value from the array and returns it.unshift( value )
— Inserts a new item at the beginning of the array.shift()
— Removes the first value from the array and returns it.reverse()
— Reverses the order of the array and returns theobservableArray
(not the underlying array).sort()
— Sorts the array contents and returns theobservableArray
. The default sort is alphabetical, but you can optionally pass a function to control how the array should be sorted. See the example undersorted
below.splice()
— Removes and returns a given number of elements starting from a given index. For example,myObservableArray.splice(1, 3)
removes three elements starting from index position 1 (i.e., the 2nd, 3rd, and 4th elements) and returns them as an array.
For more details about these observableArray
Casino match play meaning. functions, see the equivalent documentation of the standard JavaScript array functions.
sorted and reversed
sorted()
— Returns a sorted copy of the array. This is preferable tosort
if you want to leave the observable array in its original order but need to display it in a specific order.The default sort is alphabetical, but you can optionally pass a function to control how the array should be sorted. Your function should accept any two objects from the array and return a negative value if the first argument is smaller, a positive value is the second is smaller, or zero to treat them as equal. For example, to sort an array of ‘person' objects by last name, you could write:
reversed()
— Returns a reversed copy of the array.
replace, remove and removeAll
observableArray
adds some more useful methods that aren't found on JavaScript arrays by default:
replace( oldItem, newItem )
— Replaces the first value that equalsoldItem
withnewItem
.remove( someItem )
— Removes all values that equalsomeItem
and returns them as an array.remove( function (item) { return item.age < 18; } )
— Removes all values whoseage
property is less than 18, and returns them as an array.removeAll( ['Chad', 132, undefined] )
— Removes all values that equal'Chad'
,123
, orundefined
and returns them as an array.removeAll()
— Removes all values and returns them as an array.
destroy and destroyAll (Note: Usually relevant to Ruby on Rails developers only)
The destroy
and destroyAll
functions are mainly intended as a convenience for developers using Ruby on Rails:
destroy( someItem )
— Finds any objects in the array that equalsomeItem
and gives them a special property called_destroy
with valuetrue
.destroy( function (someItem) { return someItem.age < 18; } )
— Finds any objects in the array whoseage
property is less than 18, and gives those objects a special property called_destroy
with valuetrue
.destroyAll( ['Chad', 132, undefined] )
— Finds any objects in the array that equal'Chad'
,123
, orundefined
and gives them a special property called_destroy
with valuetrue
.destroyAll()
— Gives a special property called_destroy
with valuetrue
to all objects in the array.
So, what's this _destroy
thing all about? It's only really interesting to Rails developers. The convention in Rails is that, when you pass into an action a JSON object graph, the framework can automatically convert it to an ActiveRecord object graph and then save it to your database. It knows which of the objects are already in your database, and issues the correct INSERT or UPDATE statements. To tell the framework to DELETE a record, you just mark it with _destroy
set to true
.
When Knockout renders a foreach
binding with the parameter includeDestroyed: false
set, it will hide any objects marked with _destroy
equal to true
. So, you can have some kind of 'delete' button that invokes the destroy(someItem)
method on the array, and this will immediately cause the specified item to vanish from the visible UI. Later, when you submit the JSON object graph to Rails, that item will also be deleted from the database (while the other array items will be inserted or updated as usual).
Determining if a property is an observableArray
In some scenarios, it is useful to programmatically determine if you are dealing with an observableArray. Knockout provides a utility function, ko.isObservableArray
to help with this situation.
Delaying and/or suppressing change notifications
Normally, an observableArray
notifies its subscribers immediately, as soon as it's changed. But if an observableArray
is changed repeatedly or triggers expensive updates, you may get better performance by limiting or delaying change notifications. This is accomplished using the rateLimit
extender like this:
Tracking array changes
Knockout Countdown
Although you can subscribe to and access an observableArray
just like any other observable, Knockout also provides a super-fast method to find out how an observable array has changed (i.e., which items were just added, deleted, or moved). You subscribe to array changes as follows:
The main advantages of subscribing to changes:
Performance is
O(1)
in most cases, i.e., there's basically no performance implication at all, because for straightforward operations, (push
,splice
, etc.) Knockout supplies the change log without running any difference algorithm. Knockout only falls back on an algorithm if you've made an arbitrary change without using a typical array mutation function.The change log just gives you the items that actually changed.
Here are examples of how the changes are reported:
As shown above, the changes are reported as a list of added and deleted values. The indexes for deleted items refer to the original array, and the indexes for added items refer to the new array.
When items are re-ordered, as shown in the last example above, you will also get moved information. You can choose to ignore the moved information and just interpret it as the original Alpha
being deleted and a different Alpha
being added to the array's end. Or you can recognize that the moved information tells you that you can think of the added and deleted values being the same item that just changes position (by matching up the indexes).
An observableArray
has array tracking enabled at construction, but you can extend any other subscribable
(i.e. ko.observable
and ko.computed
) as follows:
Knockout Count Crossword
Knockout..
The easiest way to understand moneyline wagers is by using a $100 bet. Using the above example, the moneyline on the underdog Buccaneers was +136. At +136 odds, a $100 wager would pay $136 in profit if the Buccaneers won the game (for a total payout of $236). Bettors often like picking underdogs because they are usually 'plus' money. This side of the moneyline bet pays out more money per unit than a. A moneyline bet simply involves you picking one of two teams to win the game. No catch, no angle, just the right answer or the wrong answer. Each team/person in a matchup for a moneyline betting option is given a separate numerical value for bettors to wager on and these are called 'odds.'. Moneyline bets take the gold medal when it comes to simplicity. Pick a winner, decide if the payout you'll receive is worth the risk, make the bet, and that is it. If your team or player wins, you win. People will try and overcomplicate this, but that is all there is to it. Some bettors will bet the underdog on the moneyline as well as picking the team to cover the spread in an effort to protect themselves in case one bet hits and not the other. Moneyline Parlays. One sports betting strategy some bettors go with is parlaying moneyline plays. If you are extremely confident in two or more moneyline outcomes, combine them into your wager and cash your ticket with a higher payout. The Bottom Line on Moneyline Betting. Moneyline bets are straight forward wagers in which you are simply deciding which side you think will win. For each game on the docket, oddsmakers will designate a favorite and underdog. Which side is which will be reflected in the odds. Favorites will have negative odds, while the underdog will have positive odds.
Смотреть что такое 'Knockout' в других словарях:
knockout — knockout→k.o … Das Wörterbuch der Synonyme
knockout — knock‧out [ˈnɒk aʊt ǁ ˈnɑːk ] noun [countable] an arrangement in which people who are trying to buy the same thing agree not to compete against each other on the price: • It appears to be doubtful whether a knockout was arranged. • a knockout… … Financial and business terms
knockout — knock out , knock out knock out , n. Act of knocking out, or state of being knocked out; the act of rendering a person unconscious by a blow. [WordNet sense 1] [Webster 1913 Suppl. + WordNet 1.5] 2. a blow which causes a person to become… … The Collaborative International Dictionary of English
knockout — [näk′out΄] adj. that knocks out: said of a blow, etc. n. 1. a knocking out or being knocked out 2. a) a blow that knocks out b) Boxing a victory won when the opponent is knocked out: cf. TECHNICAL KNOCKOUT ☆ 3. Slang a very attractive or striking … English World dictionary
knockout — Adj k. o … Etymologisches Wörterbuch der deutschen sprache
knockout — (n.) also knock out, in fighting, 1887, from verbal phrase knock out to stun by a blow for a 10 count in boxing, short for to knock out of time; see KNOCK (Cf. knock) (v.) + OUT (Cf. out). Slang meaning attractive person is from 1892. To knock… … Etymology dictionary
knockout — ► NOUN 1) an act of knocking someone out. 2) Brit. a tournament in which the loser in each round is eliminated. 3) informal an extremely attractive or impressive person or thing … English terms dictionary
Knockout — KO and K.O. redirect here. For other uses, see Ko (disambiguation). For other uses of knockout , see Knockout (disambiguation). A knockout can be characterized by temporary unconsciousness. A knockout (also referred to as a K.O.) is a fight… … Wikipedia
knockout — [[t]nɒ̱kaʊt[/t]] knockouts also knock out 1) N COUNT: also by N In boxing, a knockout is a situation in which a boxer wins the fight by making his opponent fall to the ground and be unable to stand up before the referee has counted to ten. 2) ADJ … English dictionary
knockout — knock|out1 [ˈnɔk aut US ˈna:k ] n 1.) when a ↑boxer hits his opponent so hard that he falls down and cannot get up again ▪ The fight ended in a knockout. 2.) informal someone or something that is very attractive or successful ▪ Her dress was a… … Dictionary of contemporary English
Книги
- Property vs Shares. Discover Your Knockout Investment Strategy, Peter Koulizos. A comparison of property versus shares and how to find the right mix for a profitable portfolio Almost every investor eventually considers the question: which is the better investment,… ПодробнееКупить за 2081.26 рубэлектронная книга
- The Little Book That Builds Wealth. The Knockout Formula for Finding Great Investments, Pat Dorsey. In The Little Book That Builds Wealth, author Pat Dorsey—the Director of Equity Research for leading independent investment research provider Morningstar, Inc.—reveals why competitive… ПодробнееКупить за 1947.28 рубэлектронная книга
- Knockout Knits: New Tricks for Scarves, Hats, Jewelry, and Other Accessories, Laura Nelkin. Knitters love accessories. They're fast, often require only a skein or two of yarn, and make amazingly versatile gifts for friends and family. Small knits are also the perfect way to try… ПодробнееКупить за 1589 руб