mirror of https://github.com/tc39/test262.git
27 lines
783 B
JavaScript
27 lines
783 B
JavaScript
// Copyright (C) 2016 the V8 project authors. All rights reserved.
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// This code is governed by the BSD license found in the LICENSE file.
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/*---
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es6id: 23.1.1
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description: Subclassing the Map object
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info: |
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23.1.1 The Map Constructor
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...
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The Map constructor is designed to be subclassable. It may be used as the
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value in an extends clause of a class definition. Subclass constructors that
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intend to inherit the specified Map behaviour must include a super call to the
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Map constructor to create and initialize the subclass instance with the
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internal state necessary to support the Map.prototype built-in methods.
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---*/
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class M extends Map {}
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var map = new M([{ 'foo': 'bar' }]);
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assert.sameValue(map.size, 1);
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map.set('bar', 'baz');
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assert.sameValue(map.size, 2);
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