This is not a complete list.
Collections
Finding
_.filter(list, (n) => n % 2) //=> Array
_.find(list, (n) => n % 2) //=> item
_.findRight(list, ...) //=> item
Works for both arrays and objects.
Accessing
_.at([ abcd ], 0) //=> [ a ] - same as list[0]
_.at([ abcd ], [ 0, 1 ]) //=> [ ab ]
Set/get
_.set(object, 'users[0].name', value)
_.get(object, 'users[0].name')
_.get(object, ['users', 0, 'name'])
Iteration
_.forEach(list, (item, i) => ...)
_.forEachRight(list, ...)
_.map(list, ...)
_.every(users, (u) => u.active) //=> true|false (aka _.all)
_.any(users, ...) //=> true|false (aka _.some)
Array
Arrays
_.chunk([ abcd ], 2) //=> [ [ab], [cd] ]
_.compact(list)
_.fill(Array(4), 'x') //=> [ 'x', 'x', 'x', 'x' ]
_.flatten
_.flattenDeep
Filtering
_.drop([ abcdef ], 2) //=> [ cdef ]
_.dropRight([ abcdef ], 2) //=> [ abcd ]
_.take([ abcdef ], 2) //=> [ ab ]
_.takeRight([ abcdef ], 2) //=> [ de ]
_.slice([ abcdef ], 2, 4) //=> [ cd ]
_.initial([ abcdef ]) //=> [ abcde ] - dropRight(list, 1)
_.rest([ abcdef ]) //=> [ bcdef ] - takeRight(list, 1)
_.dropWhile(list, 'active') // works like filter
_.dropWhile(list, 'active', true)
_.dropWhile(list, { active: true })
_.dropWhile(list, (n) => ...)
_.dropRightWhile(list, ...)
_.without([ abcde ], b) //=> [ acde ]
_.remove(list, (n) => n % 2)
Accessing
_.first([ abcdef ]) //=> a
_.last([ abcdef ]) //=> f
Sets
_.uniq()
_.difference([ abc ], [ bc ]) //=> [ a ]
_.intersection([ abc ], [ bcd ]) //=> [ bc ]
_.union([ abc ], [ bcd ]) //=> [ abcd ] (unique)
Array#concat()
Indexes
_.findIndex
_.findLastIndex
_.sortedIndex(list, val)
_.sortedLastIndex(list, val)
_.indexOf(list, val)
Functions
Currying
greet = (greeting, name) => `${greeting}, ${name}!`
fn = _.partial(fn, 'hi')
fn('joe') //=> 'hi, joe!'
_.partial(fn, 'joe')
fn('yo') //=> 'yo, joe!'
_.curry(greet)('hi') //=> function(name)
_.curryRight(greet)('joe') //=> function(greet)
Decorating functions
Throttling
_.throttle(fn)
_.debounce(fn)
Limiting
_.before(5, fn) // only works 5 times
_.after(5, fn) // works only after 5 times
_.once(fn) // like _.before(fn, 1)
Etc
_.wrap(_.escape, (name) => `hi ${name}`)
// same as doing `name = _.escape(name)`
_.delay(fn, 2000)
_.negate(fn)
_.memoize(fn)
_.memoize(fn, ...)
Strings
Capitalization
_.capitalize('hello world') //=> 'Hello world'
_.startCase('hello_world') //=> 'Hello World'
_.snakeCase('hello world') //=> 'hello_world'
_.kebabCase('hello world') //=> 'hello-world'
_.camelCase('hello world') //=> 'helloWorld'
Padding
_.pad('abc', 8) //=> ' abc '
_.padLeft('abc', 8) //=> ' abc'
_.padLeft('abc', 8, '-') //=> '00000abc'
_.padRight(...)
Trim
_.trim(' str ')
_.trimLeft(' str ')
_.trimRight(' str ')
Etc
_.repeat('-', 2) //=> '--'
_.deburr('déjà vu') //=> 'deja vu'
_.trunc('hello world', 5) //=> 'hello...'
_.startsWith('abc', 'a') //=> true
_.endsWith('abc', 'c') //=> true
Objects
_.keys(obj)
_.values(obj)
Chaining
_([1, 2, 3])
.reduce((total, n) => total + n)
.map((n) => n * n)
.tap(console.log)
.thru((n) => n.reverse())
.value()