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    WeakSet.prototype.has()

    This is an experimental technology, part of the Harmony (ECMAScript 6) proposal.
    Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future version of browsers as the spec changes.

    Summary

    The has() method returns a boolean indicating whether an object exists in a WeakSet or not.

    Syntax

    ws.has(value);

    Parameters

    value
    Required. The object to test for presence in the WeakSet.

    Return value

    Boolean
    Returns true if an element with the specified value exists in the WeakSet object; otherwise false.

    Examples

    Example: Using the has method

    var ws = new WeakSet();
    var obj = {};
    ws.add(window);
    
    mySet.has(window);  // returns true
    mySet.has(obj);     // returns false
    

    Specifications

    Specification Status Comment
    ECMAScript 6 (ECMA-262)
    The definition of 'WeakSet.prototype.has' in that specification.
    Draft Initial definition.

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
    Basic support 36 34 (34) Not supported 23 Not supported
    Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
    Basic support Not supported 34.0 (34) Not supported Not supported Not supported

    See also

    Document Tags and Contributors

    Contributors to this page: realityking, fscholz, teoli
    Last updated by: realityking,