The toUpperCase()
method of String
values returns this string converted to uppercase.
The toUpperCase()
method of String
values returns this string converted to uppercase.
toUpperCase()
None.
A new string representing the calling string converted to upper case.
The toUpperCase()
method returns the value of the string converted to uppercase. This method does not affect the value of the string itself since JavaScript strings are immutable.
console.log("alphabet".toUpperCase()); // 'ALPHABET'
this
values to strings This method will convert any non-string value to a string, when you set its this
to a value that is not a string:
const a = String.prototype.toUpperCase.call({ toString() { return "abcdef"; }, }); const b = String.prototype.toUpperCase.call(true); // prints out 'ABCDEF TRUE'. console.log(a, b);
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
toUpperCase |
1 | 12 | 1 | 3 | 1 | 18 | 4 | 10.1 | 1 | 1.0 | 4.4 | 1.0 | 0.10.0 |
© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase