Source code
Revision control
Copy as Markdown
Other Tools
// Copyright 2020 Salesforce.com, Inc. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: prod-OptionalExpression
description: >
Productions for ?. IdentifierName
info: |
OptionalChain[Yield, Await]:
?. IdentifierName
features: [optional-chaining]
---*/
const arr = [10, 11];
const obj = {
a: 'hello'
};
assert.sameValue(obj?.a, 'hello');
assert.sameValue(obj?.\u0061, 'hello');
assert.sameValue(obj?.\u{0061}, 'hello');
assert.sameValue(obj?.\u0062, undefined);
assert.sameValue(obj?.\u{0062}, undefined);
assert.sameValue(arr ?. length, 2);
assert.sameValue(arr ?. l\u0065ngth, 2);
assert.sameValue(arr ?. l\u{0065}ngth, 2);
assert.sameValue(obj?.$, undefined);
obj.$ = 42;
assert.sameValue(obj?.$, 42);
assert.sameValue(obj?._, undefined);
obj._ = 39;
assert.sameValue(obj?._, 39);
reportCompare(0, 0);