How to convert array content to uppercase?

Question

Is there a non backwards way to turn exactly one array index into an uppercase string? I don't want to split, loop or anything else, because I only need this one string.

colors = [ "red", "green", "blue" ];
red = colors[0];
redUpper = red.toUppercase();

This won't work, because toUppercase() is a string function. I know that. I'm only looking for the simplest way to achieve this.

`toUppercase()` isn't a javascript function at all. It's `toUpperCase()` — baao, Aug 18 '17 at 12:43
i second @baao comment. and your snippet should works if you use correct function `toUpperCase()` — rachmatsasongko, Aug 18 '17 at 12:45
I think this question is duplicated here: https://stackoverflow.com/questions/29719329/convert-array-into-upper-case — Krzysztof Raciniewski, Aug 18 '17 at 12:46

Erazihel · Answer 1 · 2017-08-18T13:01:04.357

10

If you only want the first element upper case, you can use the String#toUpperCase function:

const colors = [ "red", "green", "blue" ];
const redUpper = colors[0].toUpperCase();
console.log(redUpper);

If you want them all, use Array#Map.

const colors = [ "red", "green", "blue" ];
console.log(colors.map(a => a.toUpperCase()));

edited Aug 18 '17 at 13:01

answered Aug 18 '17 at 12:42

Erazihel

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_I don't want to split, loop or anything else, because I only need this one string._ – baao Aug 18 '17 at 12:43
@baao Sorry I was answering the question in the title :) answer updated – Erazihel Aug 18 '17 at 12:45
This covered both the scenario's which OP asked for. Still the downvotes when helping ? hmm. – Suresh Atta Aug 18 '17 at 12:58
I removed mine @ꜱᴜʀᴇꜱʜᴀᴛᴛᴀ – baao Aug 18 '17 at 13:16

marvel308 · Answer 2 · 2017-08-18T12:56:05.510

3

You can do it using

const colors = [ "red", "green", "blue" ];
console.log(colors.map(function(x){
    return x.toUpperCase();
}));

If you want to change the first element to uppercase then use

const colors = [ "red", "green", "blue" ];
colors[0] = colors[0].toUpperCase();
console.log(colors);

edited Aug 18 '17 at 12:56

answered Aug 18 '17 at 12:43

marvel308

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_I don't want to split, loop or anything else, because I only need this one string._ – baao Aug 18 '17 at 12:48
only the first element ? – marvel308 Aug 18 '17 at 12:48
edited for handling only first element – marvel308 Aug 18 '17 at 12:56

score 2 · Answer 3 · answered Aug 18 '17 at 12:46

2

you need to assign your value to the array element you want to change

var arr = [ "red", "green", "blue" ];
arr[0] = arr[0].toUpperCase()
console.log(arr)

answered Aug 18 '17 at 12:46

Littlee

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Mostly this is what OP failing to explain. Good catch – Suresh Atta Aug 18 '17 at 12:59

score 1 · Answer 4 · edited Aug 18 '17 at 12:59

1

colors = [ "red", "green", "blue" ];
console.log(colors[0].toUpperCase())

You have a typo error in your code: toUppercase != toUpperCase

edited Aug 18 '17 at 12:59

Suresh Atta

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answered Aug 18 '17 at 12:51

Krzysztof Raciniewski

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How to convert array content to uppercase?

4 Answers4