Javascript lacks complete string manipulation operations. This an attempt to fill that gap. List of build-in methods can be found for example from Dive Into JavaScript.
As name states this an extension for Underscore.js, but it can be used independently from _s-global variable. But with Underscore.js you can use Object-Oriented style and chaining:
_(" epeli ").chain().trim().capitalize().value()
=> "Epeli"
Download
- Development version Uncompressed with Comments 18kb
- Production version Minified 7kb
Node.js installation
npm package
npm install underscore.string
Standalone usage:
var _s = require('underscore.string');
Integrate with Underscore.js:
var _ = require('underscore');
// Import Underscore.string to separate object, because there are conflict functions (include, reverse, contains)
_.str = require('underscore.string');
// Mix in non-conflict functions to Underscore namespace if you want
_.mixin(_.str.exports());
// All functions, include conflict, will be available through _.str object
_.str.include('Underscore.string', 'string'); // => true
Or Integrate with Underscore.js without module loading
Run the following expression after Underscore.js and Underscore.string are loaded
// _.str becomes a global variable if no module loading is detected
// Mix in non-conflict functions to Underscore namespace
_.mixin(_.str.exports());
String Functions
For availability of functions in this way you need to mix in Underscore.string functions:
_.mixin(_.string.exports());
otherwise functions from examples will be available through _.string or _.str objects:
_.str.capitalize('epeli')
=> "Epeli"
numberFormat _.numberFormat(number, [ decimals=0, decimalSeparator='.', orderSeparator=','])
Formats the numbers.
_.numberFormat(1000, 2)
=> "1,000.00"
_.numberFormat(123456789.123, 5, '.', ',')
=> "123,456,789.12300"
levenshtein _.levenshtein(string1, string2)
Calculates [Levenshtein distance][ld] between two strings. [ld]: http://en.wikipedia.org/wiki/Levenshtein_distance
_.levenshtein('kitten', 'kittah')
=> 2
capitalize _.capitalize(string)
Converts first letter of the string to uppercase.
_.capitalize("foo Bar")
=> "Foo Bar"
chop _.chop(string, step)
_.chop('whitespace', 3)
=> ['whi','tes','pac','e']
clean _.clean(str)
Compress some whitespaces to one.
_.clean(" foo bar ")
=> 'foo bar'
chars _.chars(str)
_.chars('Hello')
=> ['H','e','l','l','o']
swapCase _.swapCase(str)
Returns a copy of the string in which all the case-based characters have had their case swapped.
_.swapCase('hELLO')
=> 'Hello'
include available only through _.str object, because Underscore has function with the same name.
_.str.include("foobar", "ob")
=> true
(removed) includes _.includes(string, substring)
Tests if string contains a substring.
_.includes("foobar", "ob")
=> true
includes function was removed
But you can create it in this way, for compatibility with previous versions:
_.includes = _.str.include
count _.count(string, substring)
_('Hello world').count('l')
=> 3
escapeHTML _.escapeHTML(string)
Converts HTML special characters to their entity equivalents.
_('<div>Blah blah blah</div>').escapeHTML();
=> '<div>Blah blah blah</div>'
unescapeHTML _.unescapeHTML(string)
Converts entity characters to HTML equivalents.
_('<div>Blah blah blah</div>').unescapeHTML();
=> '<div>Blah blah blah</div>'
insert _.insert(string, index, substing)
_('Hello ').insert(6, 'world')
=> 'Hello world'
isBlank _.isBlank(string)
_('').isBlank(); // => true
_('\n').isBlank(); // => true
_(' ').isBlank(); // => true
_('a').isBlank(); // => false
join _.join(separator, *strings)
Joins strings together with given separator
_.join(" ", "foo", "bar")
=> "foo bar"
lines _.lines(str)
_.lines("Hello\nWorld")
=> ["Hello", "World"]
reverse available only through _.str object, because Underscore has function with the same name.
Return reversed string:
_.str.reverse("foobar")
=> 'raboof'
splice _.splice(string, index, howmany, substring)
Like a array splice.
_('https://edtsech@bitbucket.org/edtsech/underscore.strings').splice(30, 7, 'epeli')
=> 'https://edtsech@bitbucket.org/epeli/underscore.strings'
startsWith _.startsWith(string, starts)
This method checks whether string starts with starts.
_("image.gif").startsWith("image")
=> true
endsWith _.endsWith(string, ends)
This method checks whether string ends with ends.
_("image.gif").endsWith("gif")
=> true
succ _.succ(str)
Returns the successor to str.
_('a').succ()
=> 'b'
_('A').succ()
=> 'B'
supplant
Supplant function was removed, use Underscore.js template function.
strip alias for trim
lstrip alias for ltrim
rstrip alias for rtrim
titleize _.titleize(string)
_('my name is epeli').titleize()
=> 'My Name Is Epeli'
camelize _.camelize(string)
Converts underscored or dasherized string to a camelized one
_('-moz-transform').camelize()
=> 'MozTransform'
classify _.classify(string)
Converts string to camelized class name
_('some_class_name').classify()
=> 'SomeClassName'
underscored _.underscored(string)
Converts a camelized or dasherized string into an underscored one
_('MozTransform').underscored()
=> 'moz_transform'
dasherize _.dasherize(string)
Converts a underscored or camelized string into an dasherized one
_('MozTransform').dasherize()
=> '-moz-transform'
humanize _.humanize(string)
Converts an underscored, camelized, or dasherized string into a humanized one. Also removes beginning and ending whitespace, and removes the postfix '_id'.
_(' capitalize dash-CamelCase_underscore trim ').humanize()
=> 'Capitalize dash camel case underscore trim'
trim _.trim(string, [characters])
trims defined characters from begining and ending of the string. Defaults to whitespace characters.
_.trim(" foobar ")
=> "foobar"
_.trim("_-foobar-_", "_-")
=> "foobar"
ltrim _.ltrim(string, [characters])
Left trim. Similar to trim, but only for left side.
rtrim _.rtrim(string, [characters])
Right trim. Similar to trim, but only for right side.
truncate _.truncate(string, length, truncateString)
_('Hello world').truncate(5)
=> 'Hello...'
_('Hello').truncate(10)
=> 'Hello'
prune _.prune(string, length, pruneString)
Elegant version of truncate. Makes sure the pruned string does not exceed the original length. Avoid half-chopped words when truncating.
_('Hello, world').prune(5)
=> 'Hello...'
_('Hello, world').prune(8)
=> 'Hello...'
_('Hello, world').prune(5, ' (read a lot more)')
=> 'Hello, world' (as adding "(read a lot more)" would be longer than the original string)
_('Hello, cruel world').prune(15)
=> 'Hello, cruel...'
_('Hello').prune(10)
=> 'Hello'
words _.words(str, delimiter=/\s+/)
Split string by delimiter (String or RegExp), /\s+/ by default.
_.words(" I love you ")
=> ["I","love","you"]
_.words("I_love_you", "_")
=> ["I","love","you"]
_.words("I-love-you", /-/)
=> ["I","love","you"]
_.words(" ")
=> []
sprintf _.sprintf(string format, *arguments)
C like string formatting. Credits goes to Alexandru Marasteanu. For more detailed documentation, see the original page.
_.sprintf("%.1f", 1.17)
"1.2"
pad _.pad(str, length, [padStr, type])
pads the str
with characters until the total string length is equal to the passed length
parameter. By default, pads on the left with the space char (" "
). padStr
is truncated to a single character if necessary.
_.pad("1", 8)
-> " 1";
_.pad("1", 8, '0')
-> "00000001";
_.pad("1", 8, '0', 'right')
-> "10000000";
_.pad("1", 8, '0', 'both')
-> "00001000";
_.pad("1", 8, 'bleepblorp', 'both')
-> "bbbb1bbb";
lpad _.lpad(str, length, [padStr])
left-pad a string. Alias for pad(str, length, padStr, 'left')
_.lpad("1", 8, '0')
-> "00000001";
rpad _.rpad(str, length, [padStr])
right-pad a string. Alias for pad(str, length, padStr, 'right')
_.rpad("1", 8, '0')
-> "10000000";
lrpad _.lrpad(str, length, [padStr])
left/right-pad a string. Alias for pad(str, length, padStr, 'both')
_.lrpad("1", 8, '0')
-> "00001000";
center alias for lrpad
ljust alias for rpad
rjust alias for lpad
toNumber _.toNumber(string, [decimals])
Parse string to number. Returns NaN if string can't be parsed to number.
_('2.556').toNumber()
=> 3
_('2.556').toNumber(1)
=> 2.6
strRight _.strRight(string, pattern)
Searches a string from left to right for a pattern and returns a substring consisting of the characters in the string that are to the right of the pattern or all string if no match found.
_('This_is_a_test_string').strRight('_')
=> "is_a_test_string";
strRightBack _.strRightBack(string, pattern)
Searches a string from right to left for a pattern and returns a substring consisting of the characters in the string that are to the right of the pattern or all string if no match found.
_('This_is_a_test_string').strRightBack('_')
=> "string";
strLeft _.strLeft(string, pattern)
Searches a string from left to right for a pattern and returns a substring consisting of the characters in the string that are to the left of the pattern or all string if no match found.
_('This_is_a_test_string').strLeft('_')
=> "This";
strLeftBack _.strLeftBack(string, pattern)
Searches a string from right to left for a pattern and returns a substring consisting of the characters in the string that are to the left of the pattern or all string if no match found.
_('This_is_a_test_string').strLeftBack('_')
=> "This_is_a_test";
stripTags
Removes all html tags from string.
_('a <a href="#">link</a>').stripTags()
=> 'a link'
_('a <a href="#">link</a><script>alert("hello world!")</script>').stripTags()
=> 'a linkalert("hello world!")'
toSentence _.toSentence(array, [delimiter, lastDelimiter])
Join an array into a human readable sentence.
_.toSentence(['jQuery', 'Mootools', 'Prototype'])
=> 'jQuery, Mootools and Prototype';
_.toSentence(['jQuery', 'Mootools', 'Prototype'], ', ', ' unt ')
=> 'jQuery, Mootools unt Prototype';
toSentenceSerial _.toSentenceSerial(array, [delimiter, lastDelimiter])
The same as toSentence
, but adjusts delimeters to use Serial comma.
_.toSentenceSerial(['jQuery', 'Mootools'])
=> 'jQuery and Mootools';
_.toSentenceSerial(['jQuery', 'Mootools', 'Prototype'])
=> 'jQuery, Mootools, and Prototype'
_.toSentenceSerial(['jQuery', 'Mootools', 'Prototype'], ', ', ' unt ');
=> 'jQuery, Mootools, unt Prototype';
repeat _.repeat(string, count, [separator])
Repeats a string count times.
_.repeat("foo", 3)
=> 'foofoofoo';
_.repeat("foo", 3, "bar")
=> 'foobarfoobarfoo'
surround _.surround(string, wrap)
Surround a string with another string.
_.surround("foo", "ab")
=> 'abfooab';
quote _.quote(string, quoteChar) or _.q(string, quoteChar)
Quotes a string. quoteChar
defaults to "
.
_.quote('foo', quoteChar)
=> '"foo"';
unquote _.unquote(string, quoteChar)
Unquotes a string. quoteChar
defaults to "
.
_.unquote('"foo"')
=> 'foo';
_.unquote("'foo'", "'")
=> 'foo';
slugify _.slugify(string)
Transform text into a URL slug. Replaces whitespaces, accentuated, and special characters with a dash.
_.slugify("Un éléphant à l'orée du bois")
=> 'un-elephant-a-loree-du-bois';
Caution: this function is charset dependent
naturalCmp array.sort(_.naturalCmp)
Naturally sort strings like humans would do.
['foo20', 'foo5'].sort(_.naturalCmp)
=> [ 'foo5', 'foo20' ]
toBoolean _.toBoolean(string) or _.toBool(string)
Turn strings that can be commonly considered as booleas to real booleans. Such as "true", "false", "1" and "0". This function is case insensitive.
_.toBoolean("true")
=> true
_.toBoolean("FALSE")
=> false
_.toBoolean("random")
=> undefined
It can be customized by giving arrays of truth and falsy value matcher as parameters. Matchers can be also RegExp objects.
_.toBoolean("truthy", ["truthy"], ["falsy"])
=> true
_.toBoolean("true only at start", [/^true/])
=> true
Roadmap
Any suggestions or bug reports are welcome. Just email me or more preferably open an issue.
Problems
We lose two things for include
and reverse
methods from _.string
:
- Calls like
_('foobar').include('bar')
aren't available; - Chaining isn't available too.
But if you need this functionality you can create aliases for conflict functions which will be convenient for you:
_.mixin({
includeString: _.str.include,
reverseString: _.str.reverse
})
// Now wrapper calls and chaining are available.
_('foobar').chain().reverseString().includeString('rab').value()
Standalone Usage
If you are using Underscore.string without Underscore. You also have _.string
namespace for it and _.str
alias
But of course you can just reassign _
variable with _.string
_ = _.string
Changelog
2.3.3
- Add
toBoolean
- Add
unquote
- Add quote char option to
quote
- Support dash-separated words in
titleize
- Full changelog
2.3.2
- Add
naturalCmp
- Bug fix to
camelize
- Add ă, ș, ț and ś to
slugify
- Doc updates
- Add support for component
- Full changelog
2.3.1
- Bug fixes to
escapeHTML
,classify
,substr
- Faster
count
- Documentation fixes
- Full changelog
2.3.0
- Added
numberformat
method - Added
levenshtein
method (Levenshtein distance calculation) - Added
swapCase
method - Changed default behavior of
words
method - Added
toSentenceSerial
method - Added
surround
andquote
methods
2.2.1
- Same as 2.2.0 (2.2.0rc on npm) to fix some npm drama
2.2.0
- Capitalize method behavior changed
- Various perfomance tweaks
2.1.1###
- Fixed words method bug
- Added classify method
2.1.0
- AMD support
- Added toSentence method
- Added slugify method
- Lots of speed optimizations
2.0.0
- Added prune, humanize functions
- Added .string (.str) namespace for Underscore.string library
- Removed includes function
For upgrading to this version you need to mix in Underscore.string library to Underscore object:
_.mixin(_.string.exports());
and all non-conflict Underscore.string functions will be available through Underscore object.
Also function includes
has been removed, you should replace this function by _.str.include
or create alias _.includes = _.str.include
and all your code will work fine.
1.1.6
- Fixed reverse and truncate
- Added isBlank, stripTags, inlude(alias for includes)
- Added uglifier compression
1.1.5
- Added strRight, strRightBack, strLeft, strLeftBack
1.1.4
- Added pad, lpad, rpad, lrpad methods and aliases center, ljust, rjust
- Integration with Underscore 1.1.6
1.1.3
- Added methods: underscored, camelize, dasherize
- Support newer version of npm
1.1.2
- Created functions: lines, chars, words functions
1.0.2
- Created integration test suite with underscore.js 1.1.4 (now it's absolutely compatible)
- Removed 'reverse' function, because this function override underscore.js 'reverse'
Contribute
- Fork & pull request. Don't forget about tests.
- If you planning add some feature please create issue before.
Otherwise changes will be rejected.
Contributors list
Licence
The MIT License
Copyright (c) 2011 Esa-Matti Suuronen esa-matti@suuronen.org
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.