Object utilities.
Bind methods of the target object to always execute on its own context (ovewritting the original function).
See: function/bind
var view = {
name: 'Lorem Ipsum',
logNameOnClick: function() {
console.log(this.name);
}
};
// binds all methods by default
bindAll(view);
jQuery('#docs').on('click', view.logNameOnClick);
You can also specify the list of methods that you want to bind (in case you just want to bind a few of them).
// only the listed methods will be bound to `obj` context
bindAll(obj, 'logNameOnClick', 'doAwesomeStuffOnDrag');
Similar to Array/contains. Checks if Object contains value.
var obj = {
a: 1,
b: 2,
c: 'bar'
};
contains(obj, 2); // true
contains(obj, 'foo'); // false
Recursively tests whether two objects contain the same keys and equal values.
callback
specifies the equality comparison function used to compare
non-object values. It defaults to using the strict equals (===
) operator.
If the values are both an object, it will recurse into the objects, checking if
their keys/values are equal. It will only check the keys and values contained
by the objects; it will not check the objects' prototypes. If the either of
the values are not objects, they will be checked using the callback
function.
Example:
deepEquals({ a: 1 }, { a: 1 }); // true
deepEquals({ value: { a: 1 } }, { value: { a: 1 } }); // true
deepEquals({ value: { a: 1 } }, { value: { a: 2 } }); // false
deepEquals({ value: { a: 1 } }, { value: { a: 1, b: 2 } }); // false
deepEquals({}, null); // false
deepEquals(null, null); // true
deepEquals(
{ a: { b: 1 } },
{ a: { b: '1' } },
function(a, b) { return a == b; }); // true
See: equals()
Fill missing properties recursively.
It's different from deepMixIn
since it won't override any existing property.
It's also different from merge
since it won't clone child objects during the
process.
It returns the target object and mutates it in place.
See: fillIn()
, deepMixIn()
, merge()
var base = {
foo : {
bar : 123
},
lorem : 'ipsum'
};
var options = deepFillIn({foo : { baz : 45 }, lorem : 'amet'}, base);
// > {foo: {bar:123, baz : 45}, lorem : 'amet'}
Recursively checks if object contains all properties/value pairs. When both the target and pattern values are arrays, it checks that the target value contain matches for all the items in the pattern array (independent of order).
var john = {
name: 'John',
age: 22,
pets: [
{ type: 'cat', name: 'Grumpy Cat' },
{ type: 'dog', name: 'Hawk' }
]
};
deepMatches(john, { name: 'John' }); // true
deepMatches(john, { age: 21 }); // false
deepMatches(john, { pets: [ { type: 'cat' } ] }); // true
deepMatches(john, { pets: [ { name: 'Hawk' } ] }); // true
deepMatches(john, { pets: [ { name: 'Hairball' } ] }); // false
See matches()
Mixes objects into the target object, recursively mixing existing child objects as well.
It will only recursively mix objects if both (existing and new) values are plain objects.
Returns the target object. Like merge()
, but mutates the target
object, and does not clone child objects.
var target = {
foo: {
name: "foo",
id: 1
}
};
deepMixIn(target, { foo: { id: 2 } });
console.log(target); // { foo: { name: "foo", id: 2 } }
See: mixIn()
, merge()
, deepFillIn()
Tests whether two objects contain the same keys and values.
callback
specifies the equality comparison function used to compare the
values. It defaults to using the strict equals (===
) operator.
It will only check the keys and values contained by the objects; it will not
check the objects' prototypes. If either of the values are not objects, they
will be compared using the callback
function.
equals({}, {}); // true
equals({ a: 1 }, { a: 1 }); // true
equals({ a: 1 }, { a: 2 }); // false
equals({ a: 1, b: 2 }, { a: 1 }); // false
equals({ a: 1 }, { a: 1, b: 2 }); // false
equals(null, null); // true
equals(null, {}); // false
equals({ a: 1 }, { a: '1' }, function(a, b) { return a == b; }); // true
Similar to Array/every. Tests whether all properties in the object pass the test implemented by the provided callback.
var obj = {
a: 1,
b: 2,
c: 3,
d: 'string'
};
every(obj, isNumber); // false
Fill in missing properties in object with values from the defaults objects.
var base = {
foo : 'bar',
num : 123
};
fillIn({foo:'ipsum'}, base); // {foo:'ipsum', num:123}
PS: it allows merging multiple objects at once, the first ones will take precedence.
See: mixIn()
, merge()
, deepFillIn()
Returns a new object containing all properties where callback
returns true,
similar to Array/filter. It does not use properties from the object's
prototype.
Callback receives the same arguments as forOwn()
.
See: forOwn()
, forIn()
, pick()
var obj = {
foo: 'value',
bar: 'bar value'
};
// returns { bar: 'bar value' }
filter(obj, function(v) { return value.length > 5; });
// returns { foo: 'value' }
filter(obj, function(v, k) { return k === 'foo'; });
Loops through all the properties in the Object and returns the first one that passes a truth test (callback), similar to Array/find. Unlike Array/find, order of iteration is not guaranteed.
var obj = {
a: 'foo',
b: 12
};
find(obj, isString); // 'foo'
find(obj, isNumber); // 12
Iterate over all properties of an Object, similar to Array/forEach.
It avoids don't enum bug on IE. It will iterate over inherited (enumerable) properties from the prototype.
It allows exiting the iteration early by returning false
on the callback.
See: forOwn()
, keys()
, values()
Callback will receive the following arguments:
function Foo(){
this.foo = 1;
this.bar = 2;
}
Foo.prototype.lorem = 4;
var obj = new Foo();
var result = 0;
var keys = [];
forIn(obj, function(val, key, o){
result += val;
keys.push(key);
});
console.log(result); // 7
console.log(keys); // ['foo', 'bar', 'lorem']
Iterate over all own properties from an Object, similar to Array/forEach.
It avoids don't enum bug on IE. Notice that it won't iterate over properties from the prototype.
It allows exiting the iteration early by returning false
on the callback.
See: forIn()
, keys()
, values()
Callback will receive the following arguments:
function Foo(){
this.foo = 1;
this.bar = 2;
}
// will be ignored
Foo.prototype.lorem = 4;
var obj = new Foo();
var result = 0;
var keys = [];
forOwn(obj, function(val, key, o){
result += val;
keys.push(key);
});
console.log(result); // 3
console.log(keys); // ['foo', 'bar']
Returns a sorted list of all enumerable properties that have function values (including inherited properties).
var obj = {
foo : function(){},
bar : 'baz'
};
functions(obj); // ['foo']
Returns nested property value. Will return undefined
if property doesn't
exist.
See: set()
, namespace()
, has()
var lorem = {
ipsum : {
dolor : {
sit : 'amet'
}
}
};
get(lorem, 'ipsum.dolor.sit'); // "amet"
get(lorem, 'foo.bar'); // undefined
Checks if object contains a child property. Useful for cases where you need to check if an object contain a nested property. It will get properties inherited by the prototype.
var a = {
b : {
c : 123
}
};
has(a, 'b.c'); // true
has(a, 'foo.c'); // false
if( has(a, 'foo.c') ){ // false
// ...
}
if( a.foo.c ){ // ReferenceError: `foo` is not defined
// ...
}
Safer Object.hasOwnProperty
. Returns a boolean indicating whether the object
has the specified property.
see: has()
var obj = {
foo: 1,
hasOwnProperty : 'bar'
};
obj.hasOwnProperty('foo'); // ERROR! hasOwnProperty is not a function
hasOwn(obj, 'foo'); // true
hasOwn(obj, 'hasOwnProperty'); // true
hasOwn(obj, 'toString'); // false
Returns an array of all own enumerable properties found upon a given object.
It will use the native Object.keys
if present.
PS: it won't return properties from the prototype.
var obj = {
foo : 1,
bar : 2,
lorem : 3
};
keys(obj); // ['foo', 'bar', 'lorem']
Returns a new object where the property values are the result of calling the callback for each property in the original object, similar to Array/map.
The callback function receives the same arguments as in forOwn()
.
See: forOwn()
var obj = { foo: 1, bar: 2 },
data = { foo: 0, bar: 1 };
map(obj, function(v) { return v + 1; }); // { foo: 2, bar: 3 }
map(obj, function(v, k) { return k; }); // { foo: "foo", bar: "bar" }
map(obj, function(v, k) { return this[k]; }, data); // { foo: 0, bar: 1 }
Checks if object contains all properties/values pairs. Useful for validation and filtering.
var john = {age:25, hair:'long', beard:true};
var mark = {age:27, hair:'short', beard:false};
var hippie = {hair:'long', beard:true};
matches(john, hippie); // true
matches(mark, hippie); // false
See deepMatches()
Deep merges objects. Note that objects and properties will be cloned during the process to avoid undesired side effects. It return a new object and won't affect source objects.
var obj1 = {a: {b: 1, c: 1, d: {e: 1, f: 1}}};
var obj2 = {a: {b: 2, d : {f : 'yeah'} }};
merge(obj1, obj2); // {a: {b : 2, c : 1, d : {e : 1, f : 'yeah'}}}
See: deepMixIn()
, deepFillIn()
Returns maximum value inside object or use a custom iterator to define how items should be compared. Similar to Array/max.
See: min()
max({a: 100, b: 2, c: 1, d: 3, e: 200}); // 200
max({a: 'foo', b: 'lorem', c: 'amet'}, function(val){
return val.length;
}); // 'lorem'
Returns minimum value inside object or use a custom iterator to define how items should be compared. Similar to Array/min.
See: max()
min({a: 100, b: 2, c: 1, d: 3, e: 200}); // 1
min({a: 'foo', b: 'lorem', c: 'amet'}, function(val){
return val.length;
}); // 'foo'
Combine properties from all the objects into first one.
This method affects target object in place, if you want to create a new Object pass an empty object as first parameter.
target
(Object) : Target Object....objects
(...Object) : Objects to be combined (0...n objects).var a = {foo: "bar"};
var b = {lorem: 123};
mixIn({}, a, b); // {foo: "bar", lorem: 123}
console.log(a); // {foo: "bar"}
mixIn(a, b); // {foo: "bar", lorem: 123}
console.log(a); // {foo: "bar", lorem: 123}
Creates an empty object inside namespace if not existent. Will return created object or existing object.
var obj = {};
namespace(obj, 'foo.bar'); // {}
console.log(obj); // {foo:{bar:{}}}
Return a copy of the object that contains only the whitelisted keys.
See: filter()
var user = {
firstName : 'John',
lastName : 'Doe',
dob : '1985/07/23',
gender : 'male'
};
// can pass an array of keys as second argument
var keys = ['firstName', 'dob']
pick(user, keys); // {firstName:"John", dob: "1985/07/23"}
// or multiple arguments
pick(user, 'firstName', 'lastName'); // {firstName:"John", lastName: "Doe"}
Extract an object containing property values with keys as they appear in the passed object.
var users = {
first: {
name : 'John',
age : 21
},
second: {
name : 'Mary',
age : 25
}
};
pluck(users, 'name'); // {first: 'John', second: 'Mary'} );
pluck(users, 'age'); // {first: 21, second: 25} );
Similar to Array/reduce.
Apply a function against an accumulator and each property of the object (order is undefined) as to reduce it to a single value.
var obj = {a: 1, b: 2, c: 3, d: 4};
function sum(prev, cur, key, list) {
compare1.push(prev);
return prev + cur;
}
reduce(obj, sum); // 10
Returns a new object containing all properties where callback
returns true,
similar to Array/reject. It does not use properties from
the object's prototype. Opposite of filter()
.
See filter()
var obj = {a: 1, b: 2, c: 3, d: 4, e: 5};
reject(obj, function(x) { return (x % 2) !== 0; }); // {b: 2, d: 4}
Returns an array of all own enumerable properties values found upon a given object.
PS: it won't return properties from the prototype.
var obj = {
foo : 1,
bar : 2,
lorem : 3
};
values(obj); // [1, 2, 3]
Sets a nested property value.
See: get()
, namespace()
var obj = {};
set(obj, 'foo.bar', 123);
console.log(obj.foo.bar); // 123
console.log(obj); // {foo:{bar:123}}
Returns the count of own enumerable properties found upon a given object.
PS: it won't return properties from the prototype.
var obj = {
foo : 1,
bar : 2,
lorem : 3
};
size(obj); // 3
Similar to Array/some. Tests whether any properties in the object pass the test implemented by the provided callback.
var obj = {
a: 1,
b: 2,
c: 3,
d: 'string'
};
some(obj, isNumber); // true
Delete object property if existent and returns a boolean indicating succes. It
will also return true
if property doesn't exist.
Some properties can't be deleted, to understand why check this article.
See: set()
var lorem = {
ipsum : {
dolor : {
sit : 'amet'
}
}
};
unset(lorem, 'ipsum.dolor.sit'); // true
console.log(lorem.ipsum.dolor); // {}
unset(lorem, 'foo.bar'); // true