@stdlib/string-left-pad

Left Pad

Left pad a string.

Installation

npm install @stdlib/string-left-pad

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' ); // => length 12
  // returns 'beepbeepboop'
  
  str = str.substring( str.length-10 ); // => length 10
  // returns 'epbeepboop'
  

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

Installation

To use the module as a general utility, install the module globally

npm install -g @stdlib/string-left-pad

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

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2021. The Stdlib Authors.