File: controlFlowForInStatement2.js

package info (click to toggle)
node-typescript 4.9.5%2Bds1-2
  • links: PTS, VCS
  • area: main
  • in suites: sid, trixie
  • size: 533,908 kB
  • sloc: javascript: 2,018,330; makefile: 7; sh: 1
file content (43 lines) | stat: -rw-r--r-- 729 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
//// [controlFlowForInStatement2.ts]
const keywordA = 'a';
const keywordB = 'b';

type A = { [keywordA]: number };
type B = { [keywordB]: string };

declare const c: A | B;

if ('a' in c) {
    c; // narrowed to `A`
}

if (keywordA in c) {
    c; // also narrowed to `A`
}

let stringB: string = 'b';

if ((stringB as 'b') in c) {
    c; // narrowed to `B`
}

if ((stringB as ('a' | 'b')) in c) {
    c; // not narrowed
}

//// [controlFlowForInStatement2.js]
var keywordA = 'a';
var keywordB = 'b';
if ('a' in c) {
    c; // narrowed to `A`
}
if (keywordA in c) {
    c; // also narrowed to `A`
}
var stringB = 'b';
if (stringB in c) {
    c; // narrowed to `B`
}
if (stringB in c) {
    c; // not narrowed
}