AngularJS extend Usage Details and instance code, angularjsextend

AngularJS extend Usage Details and instance code, angularjsextend

AngularJS extend usage

Angular. extend: copy the second parameter and the first-layer attribute of the subsequent parameter (whether simple or object) to the first-layer attribute of the first parameter, that is, if it is an object, it references the same object and returns the first parameter object.

Instance 1: var r = angular. extend (B, a); copy the first attribute (whether simple or object) of object a to the first attribute of object B, that is, if it is an object, it references the same object and returns object B.

Js Code

var a = {   name : 'bijian',   address : 'shenzhen',   family : {     num : 6,     amount : '80W'   } }; var b = {}; var r = angular.extend(b, a); console.log('a:' + JSON.stringify(a)); console.log('b:' + JSON.stringify(b)); console.log('r:' + JSON.stringify(r));  b.address = 'hanzhou'; b.family.amount = '180W'; console.log('a:' + JSON.stringify(a)); console.log('b:' + JSON.stringify(b)); console.log('r:' + JSON.stringify(r)); 

Running result:

Text code

a:{"name":"bijian","address":"shenzhen","family":{"num":6,"amount":"80W"}} b:{"name":"bijian","address":"shenzhen","family":{"num":6,"amount":"80W"}} r:{"name":"bijian","address":"shenzhen","family":{"num":6,"amount":"80W"}} a:{"name":"bijian","address":"shenzhen","family":{"num":6,"amount":"180W"}} b:{"name":"bijian","address":"hanzhou","family":{"num":6,"amount":"180W"}} r:{"name":"bijian","address":"hanzhou","family":{"num":6,"amount":"180W"}} 

Example 2: var r = angular. extend (B, a, z); copies the first attribute (simple attribute or object) of objects a and z to the first attribute of object B, that is, if it is an object, it references the same object and returns object B.

Js Code

Var a = {name: 'bijian ', address: 'shenzhen', family: {num: 6, amount: '80w' }}; var z = {family: {amount: '150w', mainSource: 'operating company '}}; var B ={}; var r = angular. extend (B, a, z); console. log ('a: '+ JSON. stringify (a); console. log ('B:' + JSON. stringify (B); console. log ('R: '+ JSON. stringify (r); B. address = 'hanzhou'; B. family. amount = '180w'; console. log ('a: '+ JSON. stringify (a); console. log ('B:' + JSON. stringify (B); console. log ('R: '+ JSON. stringify (r ));

Running result:

Text code

A: {"name": "bijian", "address": "shenzhen", "family": {"num": 6, "amount ": "80 W"} B: {"name": "bijian", "address": "shenzhen", "family": {"amount": "150 W ", "mainSource": "Operating Company" }}r: {"name": "bijian", "address": "shenzhen", "family": {"amount ": "150 W", "mainSource": "Operating Company"} a: {"name": "bijian", "address": "shenzhen", "family ": {"num": 6, "amount": "80 W"} B: {"name": "bijian", "address": "hanzhou", "family ": {"amount": "180 W", "mainSource": "Operating Company" }}r: {"name": "bijian", "address": "hanzhou ", "family": {"amount": "180 W", "mainSource": "Operating Company "}}

More instances are not as simple, direct, and accurate as the source code. The source code of angular. extend is as follows:

Js Code

/**  * @ngdoc function  * @name angular.extend  * @function  *  * @description  * Extends the destination object `dst` by copying all of the properties from the `src` object(s)  * to `dst`. You can specify multiple `src` objects.  *  * @param {Object} dst Destination object.  * @param {...Object} src Source object(s).  * @returns {Object} Reference to `dst`.  */ function extend(dst) {  var h = dst.$$hashKey;  forEach(arguments, function(obj){   if (obj !== dst) {    forEach(obj, function(value, key){     dst[key] = value;    });   }  });   setHashKey(dst,h);  return dst; } 

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