Lodash 是一个一致性、模块化、高性能的 JavaScript 实用工具库。
_.filter(list, (n) => n % 2) // → Array
_.find(list, (n) => n % 2) // → item
_.findLast(list, ...) // → item
Works for both arrays and objects.
// → [ a ] - same as list[0]
_.at([ abcd ], 0)
// → [ ab ]
_.at([ abcd ], [ 0, 1 ])
_.set(object, 'users[0].name', value)
_.get(object, 'users[0].name')
_.get(object, ['users', 0, 'name'])
_.forEach(list, (item, i) => ...)
_.forEachRight(list, ...)
_.map(list, ...)
// → true|false (aka _.all)
_.every(users, (u) => u.active)
// → true|false (aka _.some)
_.any(users, ...)
_.chunk([ abcd ], 2) // → [ [ab], [cd] ]
_.compact(list)
// → [ 'x', 'x', 'x', 'x' ]
_.fill(Array(4), 'x')
_.flatten
_.flattenDeep
_.drop([ abcdef ], 2)// → [ cdef ]
_.dropRight([ abcdef ], 2)// → [ abcd ]
_.take([ abcdef ], 2) // → [ ab ]
_.takeRight([ abcdef ], 2)// → [ de ]
_.slice([ abcdef ], 2, 4) // → [ cd ]
// → [ abcde ] - dropRight(list, 1)
_.initial([ abcdef ])
// → [ bcdef ] - takeRight(list, 1)
_.rest([ abcdef ])
// works like filter
_.dropWhile(list, 'active')
_.dropWhile(list, 'active', true)
_.dropWhile(list, { active: true })
_.dropWhile(list, (n) => ...)
_.dropRightWhile(list, ...)
_.without([ abcde ], b)// → [ acde ]
_.remove(list, (n) => n % 2)
_.first([ abcdef ]) // → a
_.last([ abcdef ]) // → f
_.uniq()
_.difference([ abc ], [ bc ])// → [ a ]
// → [ bc ]
_.intersection([ abc ], [ bcd ])
// → [ abcd ] (unique)
_.union([ abc ], [ bcd ])
Array#concat()
_.findIndex(list, fn)
_.findLastIndex(list, fn)
_.sortedIndex(list, val)
_.sortedLastIndex(list, val)
_.indexOf(list, val)
greet = (greeting, name) =>
`${greeting}, ${name}!`
{: .-setup}
fn = _.partial(fn, 'hi')
fn('joe') // → 'hi, joe!'
fn = _.partial(fn, 'joe')
fn('yo') // → 'yo, joe!'
// → function(name)
_.curry(greet)('hi')
// → function(greet)
_.curryRight(greet)('joe')
_.throttle(fn)
_.debounce(fn)
_.before(5, fn) // only works 5 times
_.after(5, fn) // works only after 5 times
_.once(fn) // like _.before(fn, 1)
_.wrap(_.escape, (name) => `hi ${name}`)
// same as doing `name = _.escape(name)`
_.delay(fn, 2000)
_.negate(fn)
_.memoize(fn)
_.memoize(fn, ...)
_.capitalize('hello world')// → 'Hello world'
_.startCase('hello_world')// → 'Hello World'
_.snakeCase('hello world')// → 'hello_world'
_.kebabCase('hello world')// → 'hello-world'
_.camelCase('hello world')// → 'helloWorld'
_.pad('abc', 3) // → 'abc'
_.pad('abc', 8) // → ' abc '
_.pad('abc', 8, '_-') // → '_-abc_-_'
_.padStart('abc', 3) // → 'abc'
_.padStart('abc', 6) // → ' abc'
_.padStart('abc', 6, '_-')// → '_-_abc'
_.padEnd('abc', 3) // → 'abc'
_.padEnd('abc', 6) // → 'abc '
_.padEnd('abc', 6, '_-') // → 'abc_-_'
_.trim(' str ') // → 'str'
_.trimLeft(' str ') // → 'str '
_.trimRight(' str ') // → ' str'
_.repeat('-', 2) // → '--'
_.deburr('déjà vu') // → 'deja vu'
_.trunc('hello world', 5) // → 'hello...'
_.startsWith('abc', 'a') // → true
_.endsWith('abc', 'c') // → true
_.keys(obj)
_.values(obj)
_([1, 2, 3])
.reduce((total, n) => total + n)
.map((n) => n * n)
.tap(console.log)
.thru((n) => n.reverse())
.value()