Integer in JS
Matches whole integers, including negative numbers.
Try it in the JS tester →Pattern
regexJS
^-?\d+$JavaScript / ECMAScript code
jsJavaScript
const re = new RegExp("^-?\\d+$", "");
const input = "42";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).
How the pattern works
`^-?` optionally allows a leading minus sign. `\d+` requires one or more digits. `$` anchors to end.
Examples
Input
42Matches
42
Input
-17Matches
-17
Input
3.14No match
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