mirror of https://github.com/tc39/test262.git
23 lines
575 B
JavaScript
23 lines
575 B
JavaScript
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// Copyright 2019 Google, Inc. 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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esid: prod-OptionalExpression
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description: >
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demonstrate syntax-based short-circuiting.
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info: |
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If the expression on the LHS of ?. evaluates to null/undefined, the RHS is
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not evaluated
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features: [optional-chaining]
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---*/
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const a = undefined;
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let x = 1;
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a?.[++x] // short-circuiting.
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a?.b.c(++x).d; // long short-circuiting.
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undefined?.[++x] // short-circuiting.
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undefined?.b.c(++x).d; // long short-circuiting.
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assert.sameValue(1, x);
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