4.7 KiB
4.7 KiB
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 exactlylen
, but to have alength
of at leastlen
. To generate a paddedstring
having alength
equal tolen
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
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: ' '.
--split sep Delimiter for stdin data. Default: '/\\r?\\n/'.
Notes
-
If the split separator is a regular expression, ensure that the
split
option is either properly escaped or enclosed in quotes.# Not escaped... $ echo -n $'beep\nboop' | lpad -len 8 --split /\r?\n/ # Escaped... $ echo -n $'beep\nboop' | lpad -len 8 --split /\\r?\\n/
-
The implementation ignores trailing delimiters.
Examples
$ lpad beep --len 10 --pad b
bbbbbbbeep
To use as a standard stream,
$ echo -n 'beep' | lpad --len 8
beep
By default, when used as a standard stream, the implementation assumes newline-delimited data. To specify an alternative delimiter, set the split
option.
$ echo -n 'boop\tbeep' | lpad --len 8 --split '\t'
boop
beep
See Also
@stdlib/string/pad
: pad a string.@stdlib/string/right-pad
: right pad a string.