Is there a better way to add x amount of white space to a string?
str = "blah";
x = 4;
for (var i = 0; i < x; i++){
str = ' ' + str;
}
return str;
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Define 'better.' Incidentally: stackoverflow.com/questions/14343844/…David Thomas– David Thomas2014-09-14 00:12:35 +00:00Commented Sep 14, 2014 at 0:12
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If performance matters, you're doing a lot of unnecessary string concatenations when x becomes high. Imagine you wanted 512 spaces. Concatenating two strings of 256 spaces would be faster than prepending a space 512 times. On my phone but this is usually called left and right padding of strings.Warty– Warty2014-09-14 00:13:12 +00:00Commented Sep 14, 2014 at 0:13
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no point having a loop if you are always adding the same amount of paddingcharlietfl– charlietfl2014-09-14 00:14:18 +00:00Commented Sep 14, 2014 at 0:14
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There's a "padding function" in web browsers. What are you trying to achieve? Why do you want those spaces?Pointy– Pointy2014-09-14 00:15:29 +00:00Commented Sep 14, 2014 at 0:15
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1Have a look at the String.repeat method: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…user2417483– user24174832014-09-14 00:17:15 +00:00Commented Sep 14, 2014 at 0:17
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6 Answers
Could do it like this, prevents the loop.
str = str + new Array(x + 1).join(' ')
6 Comments
axelduch
This gives a length of
x - 1 because join takes the element at right and the last element does not have one. So it should be new Array(x + 1).join(' ')
p e p
Also, it should be
str = new Array(x+1).join(' ') + str;. Your version pads on the wrong side.
Declan Cook
Durp, you are correct this pads to the right. I didn't read the question properly. Guess its to late in the night for me.
K3NN3TH
it is all good, i figured out to put it on the other side, just waiting for time to run out to give answer
p e p
Yeah definitely, I just pointed it out since @aduch also pointed something out. Very elegant solution by the way.
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In ES6 you can do the following:
str = ' '.repeat(x) + str;
At this point in time (late 2014) it's only available in Chrome and Firefox. But in two years it should be widely supported.
See the documentation for more info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/repeat
Comments
Alternatively using lodash _.padStart. Pads string on the left side if it's shorter than length.
const str = 'blah',
len = str.length,
space = 4;
console.log(_.padStart(str, len + space));
// => ' blah'<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>Or pure JavaScript:
const str = 'blah',
len = str.length,
space = 4;
console.log(str.padStart(len + space, ' '));
Comments
for example you can use repeat for the white space left or right of your string:
var j = 6;
for (i = 0; i < n; i++) {
console.log(" ".repeat(j-1)+"#".repeat(i+1))
j--;
}
Comments
You can use padStart and padEnd methods.
For eg.:
const str1 = 'Hello';
const str2 = 'World';
const str3 = str1.padEnd(2,' ')+str2.padStart(1,' ');
console.log(str3);
1 Comment
TryCatchFinally
.padStart() with whitespace as fill string not working foe me
var message = 'stack' + Array(6).fill('\xa0').join('') + 'overflow'
console.log(message);
var message = 'stack' + Array(6).fill('\xa0').join('') + 'overflow'
console.log(message);