Left Pad

Left pad a string.

Usage

var lpad = require( '@stdlib/string/left-pad' );

lpad( str, len[, pad] )

Left pads a string such that the padded string has a length of at least len.

var str = lpad( 'a', 5 );
// returns '    a'

By default, an input string is padded with spaces. To pad with a different character or sequence of characters, provide a pad string.

var str = lpad( 'beep', 10, 'b' );
// returns 'bbbbbbbeep'

str = lpad( 'boop', 12, 'beep' );
// returns 'beepbeepboop'

Notes

  • An output string is not guaranteed to have a length of exactly len, but to have a length of at least len. To generate a padded string having a length equal to len

    var str = lpad( 'boop', 10, 'beep' );
    // returns 'beepbeepboop' => length 12
    
    str = str.substring( str.length-10 );
    // returns 'epbeepboop' => length 10
    

Examples

var round = require( '@stdlib/math/base/special/round' );
var randu = require( '@stdlib/random/base/randu' );
var lpad = require( '@stdlib/string/left-pad' );

var str = 'beep';
var n;
var i;

for ( i = 0; i < 100; i++ ) {
    n = round( randu()*10 ) + str.length;
    console.log( lpad( str, n, 'b' ) );
}

CLI

Usage

Usage: lpad [options] [<string>] --len=<length>

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --len length          Minimum string length.
         --pad str             String used to pad. Default: ' '.

Examples

$ lpad beep --len 10 --pad b
bbbbbbbeep

To use as a standard stream,

$ echo -n 'beep' | lpad --len 8
    beep