About stdlib...
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.
The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.
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Pad a string.
npm install @stdlib/string-padvar pad = require( '@stdlib/string-pad' );Pads a string such that the padded string has a length of len.
var str = pad( 'a', 5 );
// returns 'a 'The function accepts the following options:
-
lpad:
stringused to left pad. Default:''. -
rpad:
stringused to right pad. Default:' '. -
centerRight:
booleanindicating whether to center right in the event of a tie. Default:false(i.e., center left).
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 = pad( 'a', 10, {
'lpad': 'b'
});
// returns 'bbbbbbbbba'
str = pad( 'a', 12, {
'rpad': 'b'
});
// returns 'abbbbbbbbbbb'To center an input string, provide both lpad and rpad options.
var opts = {
'lpad': 'a',
'rpad': 'c'
};
var str = pad( 'b', 11, opts );
// returns 'aaaaabccccc'When both lpad and rpad are specified and len-str.length is odd, left and right padding cannot equally split the available padding space. By default, right padding receives the extra character (i.e., the input string is left-centered).
var opts = {
'lpad': 'a',
'rpad': 'c'
};
var str = pad( 'b', 10, opts );
// returns 'aaaabccccc'To center right, set the centerRight option.
var opts = {
'lpad': 'a',
'rpad': 'c',
'centerRight': true
};
var str = pad( 'b', 10, opts );
// returns 'aaaaabcccc'-
In contrast to lpad and rpad, any padding which does not evenly divide available space is trimmed such that the returned
stringlength is alwayslen.var opts = { 'lpad': 'boop', 'rpad': 'woot' }; var str = pad( 'beep', 10, opts ); // returns 'boobeepwoo'
-
Similarly, if
len < str.length, the inputstringis trimmed.// Pad right, trim right: var str = pad( 'beep', 2 ); // returns 'be' // Pad left, trim left: str = pad( 'beep', 2, { 'lpad': 'b' }); // returns 'ep' // Pad both, trim both: str = pad( 'beep', 2, { 'lpad': '@', 'rpad': '!' }); // returns 'ee' // Pad both, trim both starting from left: str = pad( 'abcdef', 3, { 'lpad': '@', 'rpad': '!' }); // returns 'cde' // Pad both, trim both starting from right: str = pad( 'abcdef', 3, { 'lpad': '@', 'rpad': '!', 'centerRight': true }); // returns 'bcd'
var round = require( '@stdlib/math-base-special-round' );
var randu = require( '@stdlib/random-base-randu' );
var pad = require( '@stdlib/string-pad' );
var str = 'boop';
var out;
var len;
var i;
for ( i = 0; i < 100; i++ ) {
len = round( randu()*10.0 ) + str.length;
out = pad( str, len, {
'lpad': 'beep',
'rpad': 'p'
});
console.log( '%s. %d. %d.', out, len, out.length );
}-
@stdlib/string-pad-cli: CLI package for use as a command-line utility. -
@stdlib/string-left-pad: left pad a string. -
@stdlib/string-right-pad: right pad a string.
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.
See LICENSE.
Copyright © 2016-2024. The Stdlib Authors.