Source code
Revision control
Copy as Markdown
Other Tools
// Copyright 2019 Google, Inc. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: prod-OptionalExpression
description: >
various optional chain expansions
info: |
OptionalChain[Yield, Await]:
?.[Expression]
?.IdentifierName
?.Arguments
?.TemplateLiteral
OptionalChain [Expression]
OptionalChain .IdentifierName
OptionalChain Arguments[?Yield, ?Await]
OptionalChain TemplateLiteral
features: [optional-chaining]
---*/
const arr = [10, 11];
const obj = {
a: 'hello',
b: {val: 13},
c(arg1) {
return arg1 * 2;
},
arr: [11, 12]
};
const i = 0;
// OptionalChain: ?.[Expression]
assert.sameValue(11, arr?.[i + 1]);
// OptionalChain: ?.IdentifierName
assert.sameValue('hello', obj?.a);
// OptionalChain: ?.Arguments
const fn = (arg1, arg2) => {
return arg1 + arg2;
}
assert.sameValue(30, fn?.(10, 20));
// OptionalChain: OptionalChain [Expression]
assert.sameValue(12, obj?.arr[i + 1]);
// OptionalChain: OptionalChain .IdentifierName
assert.sameValue(13, obj?.b.val);
// OptionalChain: OptionalChain Arguments
assert.sameValue(20, obj?.c(10));
reportCompare(0, 0);