_(value)
Creates a lodash
object, which wraps the given value
, to enable method chaining.
In addition to Lo-Dash methods, wrappers also have the following Array
methods:
concat
, join
, pop
, push
, reverse
, shift
, slice
, sort
, splice
, and unshift
Chaining is supported in custom builds as long as the value
method is implicitly or explicitly included in the build.
The chainable wrapper functions are:
after
, assign
, bind
, bindAll
, bindKey
, chain
, compact
, compose
, concat
, countBy
, createCallback
, debounce
, defaults
, defer
, delay
, difference
, filter
, flatten
, forEach
, forIn
, forOwn
, functions
, groupBy
, initial
, intersection
, invert
, invoke
, keys
, map
, max
, memoize
, merge
, min
, object
, omit
, once
, pairs
, partial
, partialRight
, pick
, pluck
, push
, range
, reject
, rest
, reverse
, shuffle
, slice
, sort
, sortBy
, splice
, tap
, throttle
, times
, toArray
, transform
, union
, uniq
, unshift
, unzip
, values
, where
, without
, wrap
, and zip
The non-chainable wrapper functions are:
clone
, cloneDeep
, contains
, escape
, every
, find
, has
, identity
, indexOf
, isArguments
, isArray
, isBoolean
, isDate
, isElement
, isEmpty
, isEqual
, isFinite
, isFunction
, isNaN
, isNull
, isNumber
, isObject
, isPlainObject
, isRegExp
, isString
, isUndefined
, join
, lastIndexOf
, mixin
, noConflict
, parseInt
, pop
, random
, reduce
, reduceRight
, result
, shift
, size
, some
, sortedIndex
, runInContext
, template
, unescape
, uniqueId
, and value
The wrapper functions first
and last
return wrapped values when n
is passed, otherwise they return unwrapped values.
Aliases
chain
Arguments
value
(Mixed): The value to wrap in alodash
instance.
Returns
(Object): Returns a lodash
instance.
Example
var wrapped = _([1, 2, 3]);
// returns an unwrapped value
wrapped.reduce(function(sum, num) {
return sum + num;
});
// => 6
// returns a wrapped value
var squares = wrapped.map(function(num) {
return num * num;
});
_.isArray(squares);
// => false
_.isArray(squares.value());
// => true
_.tap(value, interceptor)
Invokes interceptor
with the value
as the first argument, and then returns value
. The purpose of this method is to “tap into” a method chain, in order to perform operations on intermediate results within the chain.
Arguments
value
(Mixed): The value to pass tointerceptor
.interceptor
(Function): The function to invoke.
Returns
(Mixed): Returns value
.
Example
_([1, 2, 3, 4])
.filter(function(num) { return num % 2 == 0; })
.tap(alert)
.map(function(num) { return num * num; })
.value();
// => // [2, 4] (alerted)
// => [4, 16]
_.prototype.toString()
Produces the toString
result of the wrapped value.
Returns
(String): Returns the string result.
Example
_([1, 2, 3]).toString();
// => '1,2,3'
_.prototype.valueOf()
Extracts the wrapped value.
Aliases
value
Returns
(Mixed): Returns the wrapped value.
Example
_([1, 2, 3]).valueOf();
// => [1, 2, 3]