Built-in helper Functions All Versions
This draft deletes the entire topic.
Examples
-
The
angular.equalsfunction compares and determines if 2 objects or values are equal,angular.equalsperforms a deep comparison and returns true if and only if at least 1 of the following conditions is met.angular.equals(value1, value2)
- If the objects or values pass the
===comparison - If both objects or values are of the same type, and all of their properties are also equal by using
angular.equals - Both values are equal to
NaN - Both values represent the same regular expression's result.
This function is helpful when you need to deep compare objects or arrays by their values or results rather than just references.
Examples
angular.equals(1, 1) // true angular.equals(1, 2) // false angular.equals({}, {}) // true, note that {}==={} is false angular.equals({a: 1}, {a: 1}) // true angular.equals({a: 1}, {a: 2}) // false angular.equals(NaN, NaN) // true - If the objects or values pass the
-
The function
angular.toJsonwill take an object and serialize it into a JSON formatted string.Unlike the native function
JSON.stringify, This function will remove all properties beginning with$$(as angular usually prefixes internal properties with$$)angular.toJson(object)As data needs to be serialized before passing through a network, this function is useful to turn any data you wish to transmit into JSON.
This function is also useful for debugging as it works similarly to a
.toStringmethod would act.Examples:
angular.toJson({name: "barf", occupation: "mog", $$somebizzareproperty: 42}) // "{"name":"barf","occupation":"mog"}" angular.toJson(42) // "42" angular.toJson([1, "2", 3, "4"]) // "[1,"2",3,"4"]" var fn = function(value) {return value} angular.toJson(fn) // undefined, functions have no representation in JSON -
-
The
angular.copyfunction takes an object, array or a value and creates a deep copy of it.angular.copy()
Example:
Objects:
let obj = {name: "vespa", occupation: "princess"}; let cpy = angular.copy(obj); cpy.name = "yogurt" // obj = {name: "vespa", occupation: "princess"} // cpy = {name: "yogurt", occupation: "princess"}Arrays:
var w = [a, [b, [c, [d]]]]; var q = angular.copy(w); // q = [a, [b, [c, [d]]]]At the above example
angular.equals(w, q)will evaluate to true because.equalstests equality by value. howeverw === qwill evaluate to false because strict comparison between objects and arrays is done by reference. -
The
angular.isArrayfunction returns true if and only if the object or value passed to it is of the typeArray.angular.isArray(value)
Examples
angular.isArray([]) // true angular.isArray([2, 3]) // true angular.isArray({}) // false angular.isArray(17) // falseIt is the equivalent of
Array.isArray(someValue) -
The
angular.isDatefunction returns true if and only if the object passed to it is of the type Date.angular.isDate(value)
Examples
angular.isDate("lone star") // false angular.isDate(new Date()) // true -
The function
angular.isDefinedtests a value if it is definedangular.isDefined(someValue)
This is the equivalent of performing
value !== undefined; // will evaluate to true is value is definedExamples
angular.isDefined(42) // true angular.isDefined([1, 2]) // true angular.isDefined(undefined) // false angular.isDefined(null) // true
The function
angular.isUndefinedtests if a value is undefined (it is effectively the opposite ofangular.isDefined)angular.isUndefined(someValue)
This is the equivalent of performing
value === undefined; // will evaluate to true is value is undefinedOr just
!angular.isDefined(value)Examples
angular.isUndefined(42) // false angular.isUndefined(undefined) // true -
The
angular.isElementreturns true if the argument passed to it is a DOM Element or a jQuery wrapped Element.angular.isElement(elem)
This function is useful to type check if a passed argument is an element before being processed as such.
Examples:
angular.isElement(document.querySelector("body")) // true angular.isElement(document.querySelector("#some_id")) // false if "some_id" is not using as an id inside the selected DOM angular.isElement("<div></div>") // false -
The function
angular.isFunctiondetermines and returns true if and only if the value passed to is a reference to a function.The function returns a reference to the now extended destination object
angular.isFunction(fn)
Examples
var onClick = function(e) {return e}; angular.isFunction(onClick); // true var someArray = ["pizza", "the", "hut"]; angular.isFunction(someArray ); // false -
The function
angular.isStringreturns true if the object or value given to it is of the typestringangular.isString(value1)
Examples
angular.isString("hello") // true angular.isString([1, 2]) // false angular.isString(42) // falseThis is the equivalent of performing
typeof someValue === "string" -
The function angular.merge takes all the enumerable properties from the source object to deeply extend the destination object.
The function returns a reference to the now extended destination object
angular.merge(destination, source)
Examples
angular.merge({}, {}) // {} angular.merge({name: "king roland"}, {password: "12345"}) // {name: "king roland", password: "12345"} angular.merge({a: 1}, [4, 5, 6]) // {0: 4, 1: 5, 2: 6, a: 1} angular.merge({a: 1}, {b: {c: {d: 2}}}) // {"a":1,"b":{"c":{"d":2}}} -
The
angular.noopis a function that performs no operations, you passangular.noopwhen you need to provide a function argument that will do nothing.angular.noop()
A common use for
angular.noopcan be to provide an empty callback to a function that will otherwise throw an error when something else than a function is passed to it.Example:
$scope.onSomeChange = function(model, callback) { updateTheModel(model); if (angular.isFunction(callback)) { callback(); } else { throw new Error("error: callback is not a function!"); } }; $scope.onSomeChange(42, function() {console.log("hello callback")}); // will update the model and print 'hello callback' $scope.onSomeChange(42, angular.noop); // will update the modelAdditional examples:
angular.noop() // undefined angular.isFunction(angular.noop) // true -
The
angular.forEachaccepts an object and an iterator function. It then runs the iterator function over each enumerable property/value of the object. This function also works on arrays.Like the JS version of
Array.prototype.forEachThe function does not iterate over inherited properties (prototype properties), however the function will not attempt to process anullor anundefinedvalue and will just return it.angular.forEach(object, function(value, key) { // function});
Examples:
angular.forEach({"a": 12, "b": 34}, (value, key) => console.log("key: " + key + ", value: " + value)) // key: a, value: 12 // key: b, value: 34 angular.forEach([2, 4, 6, 8, 10], (value, key) => console.log(key)) // will print the array indices: 1, 2, 3, 4, 5 angular.forEach([2, 4, 6, 8, 10], (value, key) => console.log(value)) // will print the array values: 2, 4, 6, 7, 10 angular.forEach(undefined, (value, key) => console.log("key: " + key + ", value: " + value)) // undefined -
The function
angular.fromJsonwill deserialize a valid JSON string and return an Object or an Array.angular.fromJson(string|object)
Note that this function is not limited to only strings, it will output a representation of any object passed to it.
Examples:
angular.fromJson("{\"yogurt\": \"strawberries\"}") // Object {yogurt: "strawberries"} angular.fromJson('{jam: "raspberries"}') // will throw an exception as the string is not a valid JSON angular.fromJson(this) // Window {external: Object, chrome: Object, _gaq: Y, angular: Object, ng339: 3…} angular.fromJson([1, 2]) // [1, 2] typeof angular.fromJson(new Date()) // "object" -
The
angular.identityfunction returns the first argument passed to it.angular.identity(argument)
This function is useful for functional programming, you can provide this function as a default in case an expected function was not passed.
Examples:
angular.identity(42) // 42var mutate = function(fn, num) { return angular.isFunction(fn) ? fn(num) : angular.identity(num) } mutate(function(value) {return value-7}, 42) // 35 mutate(null, 42) // 42 mutate("mount. rushmore", 42) // 42 -
The
angular.isNumberfunction returns true if and only if the object or value passed to it is of the type Number, this includes +Infinity, -Infinity and NaNangular.isNumber(value)
This function will not cause a type coercion such as
"23" == 23 // trueExamples
angular.isNumber("23") // false angular.isNumber(23) // true angular.isNumber(NaN) // true angular.isNumber(Infinity) // trueThis function will not cause a type coercion such as
"23" == 23 // true -
The
angular.isObjectreturn true if and only if the argument passed to it is an object, this function will also return true for an Array and will return false fornulleven thoughtypeof nullisobject.angular.isObject(value)
This function is useful for type checking when you need a defined object to process.
Examples:
angular.isObject({name: "skroob", job: "president"}) // true angular.isObject(null) // false angular.isObject([null]) // true angular.isObject(new Date()) // true angular.isObject(undefined) // false
Sign up or log in
Save edit as a guest
Join Stack Overflow
We recognize you from another Stack Exchange Network site!
Join and Save Draft