lang2

Lang

Javascript utilities library.

Features

• All browsers support
• Unmatched performance
• Only 1.14 KB (compressed and gzipped)

Table of content

• Install
• Usage
• API
  • .camelize()
  • .capitalize()
  • .contains()
  • .each()
  • .endsWith()
  • .extend()
  • .htmlToString()
  • .indexOf()
  • .insert()
  • .isArray()
  • .isFunction()
  • .isObject()
  • .map()
  • .truncate()
• Performance
• License

Install

npm install lang2

Usage

In a browser:

<script src="path/to/lang2.js"></script>
<script>
  // window.lang is available here
</script> 

As a CommonJS module:

var Lang = require('lang2')

As AMD:

define(['lang2'], function (Lang) {
  // Use lang here
});

As a ES2015 module:

import { * as Lang } from 'lang2'

Modules

.camelize()

Converts a string to the camel case format.

Params:

Parameter	Type	Description
str	String	The string to be formatted.

Returns: String

Example:

import { camelize } from 'lang2'
 
const a = camelize('foo-bar'); // "fooBar"
const b = camelize('foo_bar'); // "fooBar"
const c = camelize('FooBar');  // "fooBar"

.capitalize()

Converts the first char of a string to the upper case.

Params:

Parameter	Type	Description
str	String	The string to be capitalized.

Returns: String

Example:

import { capitalize } from 'lang2'
 
const a = capitalize('foo bar'); // "Foo bar"

.contains()

Returns true if a given array contains a given item. Otherwise returns false.

Params:

Parameter	Type	Description
arr	Array	The array where to search.
item	*	The item to search for.

Returns: Boolean

Example:

import { contains } from 'lang2'
 
const hasBar = contains(['foo', 'bar', 'xyz'], 'bar'); // true
const hasTwo = contains([0, 1, 3], 2); // false

.each()

Executes a given function per each element of a given array.

Params:

Parameter	Type	Description
arr	Array	The array that will be used to iterate through.
callback	Function	The function to execute for each element. Takes two arguments: – * value – Number index.
thisArg	Object	The value to use as this when executing callback. Optional.

Returns: Undefined.

Example:

import { each } from 'lang2'
 
each(['foo', 'bar', 'xyz'], (item, idx) => {
  console.log(item, idx);
});
 
// "foo", 0
// "bar", 1
// "xyz", 2

.endsWith()

Determines whether a string ends with the characters of another string, returning true or false as appropriate.

Params:

Parameter	Type	Description
subjectStr	String	The string where to search.
searchStr	String	The substring to be searched for at the end of the subject string.

Returns: Boolean

Example:

import { endsWith } from 'lang2'
 
endsWith('Hello world', 'world'); // true
endsWith('Hello world', 'Hello'); // false

.extend()

Extends a given object with the contents of one or more objects.

Params:

Parameter	Type	Description
target	Object	Object to be extended.
source	Object	The object containing additional properties to extend with.

Returns: Object

Example:

import { extend } from 'lang2'
 
const obj = extend({}, { foo: 'bar' }, { baz: 'xyz' });
// { foo: "bar", baz: "xyz" }

.filter()

Creates a new array with all elements that pass the test implemented by a given function.

Params:

Parameter	Type	Description
arr	Array	The array to be filtered.
callback	Function	The function to test each element of the array. Invoked with two arguments: - * item - Number index. Return true to keep the element, false otherwise.
thisArg	Object	The value to use as this when executing callback. Optional.

Returns: Undefined

Example:

import { filter } from 'lang2'
 
const arr = filter([0, 6, 2, 11, 4], (value, idx) => {
  return value > 5;
});
 
// [0, 2, 4]

.hasOwnProps()

Checks whether a given object has any own properties. Returns true if it has at least one own property, false otherwise.

Params:

Parameter	Type	Description
obj	Object	The object to check.

Returns: Boolean

Example:

import { hasOwnProps } from 'lang2'
 
hasOwnProps({ foo: 'bar' }); // true
hasOwnProps(); // false
hasOwnProps(Object.create({
  foo: 'bar'
})); // false

.htmlToString()

Returns the text content of given HTML string.

Params:

Parameter	Type	Description
str	String	The string which might contain HTML.

Returns: String

Example:

import { htmlToString } from 'lang2'
 
const str = htmlToString('<html><span>foo</span><div>bar</div></html>'); // "foobar"

.indexOf()

Returns the first index at which a given element can be found in a given array, or -1 if it is not present.

Params:

Parameter	Type	Description
arr	Array	The array where to search.
item	*	The item to locate in the array.

Returns: Number

Example:

import { indexOf } from 'lang2'
 
const index22 = indexOf([0, 11, 22, 33], 22); // 2
const indexFoo = indexOf(['foo', 'bar', 'baz', 'foo'], 'foo'); // 0
const indexD = indexOf(['a', 'b', 'c'], 'd'); // -1

.insert()

Inserts a given item into a given array.

Params:

Parameter	Type	Description
arr	Array	Array the item to be inserted to.
item	*	The item to be inserted.
index	Number	The needed index of the item.

Returns: Undefined

Example:

.isArray()

Checks whether a given argument array or not. Returns true, if the argument is an array, false otherwise.

Params:

Parameter	Type	Description
arg	*	The argument to check.

Returns: Boolean

Example:

import { isArray } from 'lang2'
 
isArray([]); // true
isArray(''); // false
isArray(document.querySelectorAll('.foo')); // false

.isFunction()

Checks whether a given argument a function or not. Returns true, if the argument is a function, false otherwise.

Params:

Parameter	Type	Description
arg	*	The argument to check.

Returns: Boolean

Example:

import { isFunction } from 'lang2'
 
isFunction(function() {}); // true
isFunction(new Function()); // true
isFunction(null); // false

.isObject()

Checks whether a given argument an object or not. Returns true, if the argument is an object, false otherwise.

Params:

Parameter	Type	Description
arg	*	The argument to check.

Returns: Boolean

Example:

import { isObject } from 'lang2'
 
isObject({}); // true
isObject(''); // false
isObject(null); // false

.map()

Creates a new array with the results of calling a given function on every element in a given array.

Params:

Parameter	Type	Description
arr	Array	The array to iterate over.
callback	Function	The function that produces an element of the new array. Takes two arguments: – * value – Number index.
thisArg	Object	The value to use as this when executing callback. Optional.

Returns: Undefined

Example:

import { map } from 'lang2'
 
const arr = map([0, 1, 2, 3], (value, idx) => {
  return value * idx;
});
 
// [0, 1, 4, 9]

.truncate()

Truncates string with ellipsis.

Params:

Parameter	Type	Description
str	String	The string to truncate.
limit	Number	Max length of the string.
ellipsis	String	The string to indicate string is truncated. By defaults "...". Optional.
tolerance	Number	Tolerance for max length.

Returns: String.

Performance

The code of the benchmark suites can be found in benchmark/suite directory.

Start benchmark:

npm run bench

On Macbook Pro 2015 with NodeJS v4.4.7 I got the following result:

contains

Library	Ops/sec
Lang	21,322,446
Lodash	1,667,349

filter

Library	Ops/sec
Lang	6,551,629
Lodash	4,457,868
Native	2,340,407

indexOf

Library	Ops/sec
Lang	24,107,064
Lodash	20,183,423
Native	39,333,583

isArray

Library	Ops/sec
Lang	3,576,782
Lodash	52,384,477
Native	55,281,306

map

Library	Ops/sec
Lang	6,807,678
Lodash	4,917,279
Native	2,818,327

pick

Library	Ops/sec
Lang	2,176,441
Lodash	328,171

truncate

Library	Ops/sec
Lang	21,895,153
Lodash	3,937,711

LICENSE

MIT