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A quick way to check if an object is a function... |
Syntax
The .isFunction property is added to all objects, but only returns true on functions.
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var returnValue = obj.isFunction; |
Return value
| Value | Type | Notes | API Version |
|---|---|---|---|
true | Boolean | The object is a function | 1.0 |
false | Boolean | The object is not a function | 1.0 |
Examples
Pre-check that a value is not null before using .isFunction...
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var val = null;
if (val.isFunction) { // Reference Error (null.isFunction not defined)
}
if (val && val.isFunction) { // false
// val is a function
}
// alternate approach using typeOf()
if (typeOf(val) == "function") { // false
// val is a function
} |
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Availability
Requires:
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ContentsJump to:
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Type CheckingTopics:
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