Angular2中实现基于TypeScript的对象合并方法：extend()

 1   public class2type = {};
 2   ngOnInit() {
 3     this.getClass2type();
 4   }
 5  
 6   /**
 7    * 对象拷贝，参考$.extend()实现。首个参数为true时为深度拷贝，默认为false。
 8    *
 9    * @param {any} args
10    * @returns
11    * @memberof SharedService
12    */
13   extend(...args) {
14     let options, name, src, srcType, copy, copyType, copyIsArray, clone,
15       target = args[0] || {},
16       i = 1,
17       length = args.length,
18       deep = false;
19      
20     if ( typeof target === ‘boolean‘) {
21       deep = target;
22       target = args[i] || {};
23       i++;
24     }
25     if ( typeof target !== ‘object‘ && typeof target !== ‘function‘) {
26       target = {};
27     }
28     if ( i === length) {
29       target = this;
30       i--;
31     }
32     for ( ; i < length; i++ ) {
33       if ( (options = args[i]) !== null ) {
34         for ( name in options ) {
35           src = target[name];
36           copy = options[name];
37           // 若参数中字段的值就是目标参数，停止赋值，进行下一个字段的赋值
38           // 这是为了防止无限的循环嵌套
39           if ( target === copy ) {
40             continue;
41           }
42           srcType = this.isArray(src) ? ‘array‘: typeof src;
43           // 不能用typeof判断一个数组是否为数组格式，例：typeof [] -> object。如需判断的话可用‘[] instanceof Array‘方法。
44           // copyType = typeof copy;
45           if ( deep && copy && ((copyIsArray = this.isArray(copy)) || typeof copy === ‘object‘)) {
46             if ( copyIsArray ) {
47               copyIsArray = false;
48               clone = src && srcType === ‘array‘ ? src : [];
49             } else {
50               clone = src && srcType === ‘object‘ ? src: {};
51             }
52             target[name] = this.extend(deep, clone, copy);
53           } else if ( copy !== undefined ) {
54             target[name] = copy;
55           }
56         }
57       }
58     }
59     return target;
60   }
61  
62   public isArray = Array.isArray || function(obj) {
63     return this.type(obj) === ‘array‘;
64   }
65  
66   private type(obj: object) {
67     if (obj === null) {
68       return obj + "";
69     }
70     return typeof obj === ‘object‘ || typeof obj === ‘function‘ ?
71         this.class2type[this.toString.call(obj)] || ‘object‘ :
72         typeof obj;
73   }
74  
75   private getClass2type() {
76     ‘Boolean Number String Function Array Data RegExp Object Error‘.split(‘ ‘).forEach(name => {
77       this.class2type[‘[object‘ + name + ‘]‘] = name.toLowerCase();
78     });
79   }
80  
81   // 深度遍历，使用方法：
82   let newObj = this.extend(true, {}, objA, objB);