javascript - adding white space to left of string

Question

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;

Answer 1

Could do it like this, prevents the loop.

str = str + new Array(x + 1).join(' ')

Answer 2

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

Answer 3

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, ' '));

Answer 4

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--;
}