angular. copy 용법 인 스 턴 스

angular. copy (a, b): 대상 a 를 대상 b 에 깊이 복사 하고 대상 b 로 되 돌려 모든 데 이 터 를 완전히 복사 합 니 다. 장점 은 b 와 a 가 서로 의존 하지 않 는 다 는 것 입 니 다 (a, b 는 완전히 관련 이 없습니다).
        실례 1: var r = angular. copy (a, b);대상 a 의 속성 깊이 를 b 대상 에 게 복사 하고 b 대상, 즉 b, r 는 같은 대상 을 참조 합 니 다.

var a = {
	name : 'bijian',
	address : 'shenzhen',
	family : {
		num : 6,
		amount : '80W'
	}
};
var b = {};
var r = angular.copy(a, b);
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));

실행 결과:

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

 
        실례 2: var r = angular. copy (a, b);대상 a 의 속성 깊이 를 b 대상 에 게 복사 합 니 다. b 와 a 는 서로 의존 하지 않 습 니 다 (a, b 는 완전히 관련 이 없습니다)

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

a.address = 'hanzhou';
a.family.amount = '180W';
console.log('a:' + JSON.stringify(a));
console.log('b:' + JSON.stringify(b));
console.log('r:' + JSON.stringify(r));

실행 결과:

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

 
        실례 3: var r = angular. copy (a);대상 a 대상 의 속성 깊이 를 대상 r 에 복사

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

a.address = 'hanzhou';
a.family.amount = '180W';
console.log('a:' + JSON.stringify(a));
console.log('r:' + JSON.stringify(r));

실행 결과:

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

 
        사실 모든 인 스 턴 스 는 소스 코드 를 보 는 것 보다 정확 하고 직접적 입 니 다. angular. copy 소스 코드 는 다음 과 같 습 니 다.

/**
 * @ngdoc function
 * @name angular.copy
 * @function
 *
 * @description
 * Creates a deep copy of `source`, which should be an object or an array.
 *
 * * If no destination is supplied, a copy of the object or array is created.
 * * If a destination is provided, all of its elements (for array) or properties (for objects)
 *   are deleted and then all elements/properties from the source are copied to it.
 * * If  `source` is not an object or array, `source` is returned.
 *
 * Note: this function is used to augment the Object type in Angular expressions. See
 * {@link ng.$filter} for more information about Angular arrays.
 *
 * @param {*} source The source that will be used to make a copy.
 *                   Can be any type, including primitives, `null`, and `undefined`.
 * @param {(Object|Array)=} destination Destination into which the source is copied. If
 *     provided, must be of the same type as `source`.
 * @returns {*} The copy or updated `destination`, if `destination` was specified.
 */
function copy(source, destination){
  if (isWindow(source) || isScope(source)) {
    throw ngMinErr('cpws', "Can't copy! Making copies of Window or Scope instances is not supported.");
  }

  if (!destination) {
    destination = source;
    if (source) {
      if (isArray(source)) {
        destination = copy(source, []);
      } else if (isDate(source)) {
        destination = new Date(source.getTime());
      } else if (isRegExp(source)) {
        destination = new RegExp(source.source);
      } else if (isObject(source)) {
        destination = copy(source, {});
      }
    }
  } else {
    if (source === destination) throw ngMinErr('cpi', "Can't copy! Source and destination are identical.");
    if (isArray(source)) {
      destination.length = 0;
      for ( var i = 0; i < source.length; i++) {
        destination.push(copy(source[i]));
      }
    } else {
      var h = destination.$$hashKey;
      forEach(destination, function(value, key){
        delete destination[key];
      });
      for ( var key in source) {
        destination[key] = copy(source[key]);
      }
      setHashKey(destination,h);
    }
  }
  return destination;
}