Prototype Enumerable all() Method


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This method determines whether all the elements are boolean-equivalent to true, either directly or through computation by the provided iterator.

The optional context parameter is what the iterator function will be bound to. If used, the this keyword inside the iterator will point to the object given by the argument.

Syntax

Iterator.all([context]);

Return Value

  • Returns boolean true value if all the values in the iterator are true.

Example

<html>
<head>
<title>Prototype examples</title>
<script type="text/javascript" 
   src="/javascript/prototype.js">
</script>

<script>

function showResult(){

  alert( "[].all() : "  + [].all() );
  // true (empty arrays have no elements )

  alert("$R(1, 5).all() : " + $R(1, 5).all() );
  // true (all values in [1..5] are true-equivalent)

  alert("[0, 1, 2].all() : " + [0, 1, 2].all() );
  // false (with only one loop cycle: 0 is false-equivalent)

  alert([9, 10, 15].all(function(n) { return n >= 10; }) );
  //false (the iterator will return false on 9)
}

</script>
</head>

<body>

  <p>Click the button to see the result.</p>
  <br />
  <br />
  <input type="button" value="Result" onclick="showResult();"/>

</body>
</html>

To understand it in better way you can Try it yourself.


prototype_enumerating.htm

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