我需要能够在运行时合并两个(非常简单)JavaScript对象。例如,我想:
var obj1 = { food: 'pizza', car: 'ford' }
var obj2 = { animal: 'dog' }
obj1.merge(obj2);
//obj1 now has three properties: food, car, and animal
是否有一种内置的方法来实现这一点?我不需要递归,也不需要合并函数,只需要平面对象上的方法。
我需要能够在运行时合并两个(非常简单)JavaScript对象。例如,我想:
var obj1 = { food: 'pizza', car: 'ford' }
var obj2 = { animal: 'dog' }
obj1.merge(obj2);
//obj1 now has three properties: food, car, and animal
是否有一种内置的方法来实现这一点?我不需要递归,也不需要合并函数,只需要平面对象上的方法。
当前回答
我们可以装箱一个空对象,并通过for循环将它们组合起来:
变量obj1={id:“1”,name:'name'}变量obj2={c: “c”,d: “d”}var obj3={}for(obj1中的var attrname){obj3[attrname]=obj1[attrname];}for(obj2中的var attrname){obj3[attrname]=obj2[attrname];}控制台日志(obj1、obj2、obj3)
其他回答
如果您使用的是DojoToolkit,那么合并两个对象的最佳方法是使用mixin。
下面是DojoToolkit mixin的示例:
// Dojo 1.7+ (AMD)
require(["dojo/_base/lang"], function(lang){
var a = { b:"c", d:"e" };
lang.mixin(a, { d:"f", g:"h" });
console.log(a); // b:c, d:f, g:h
});
// Dojo < 1.7
var a = { b:"c", d:"e" };
dojo.mixin(a, { d:"f", g:"h" });
console.log(a); // b:c, d:f, g:h
有关详细信息,请混合。
值得一提的是,140byt.es集合的版本在最小空间内解决了这一任务,值得一试:
代码:
function m(a,b,c){for(c in b)b.hasOwnProperty(c)&&((typeof a[c])[0]=='o'?m(a[c],b[c]):a[c]=b[c])}
用途:
m(obj1,obj2);
这是原始的Gist。
使用Undercore.js,要合并对象数组,请执行以下操作:
var arrayOfObjects = [ {a:1}, {b:2, c:3}, {d:4} ];
_(arrayOfObjects).reduce(function(memo, o) { return _(memo).extend(o); });
结果是:
Object {a: 1, b: 2, c: 3, d: 4}
对于不太复杂的对象,可以使用JSON:
var obj1 = { food: 'pizza', car: 'ford' }
var obj2 = { animal: 'dog', car: 'chevy'}
var objMerge;
objMerge = JSON.stringify(obj1) + JSON.stringify(obj2);
// {"food": "pizza","car":"ford"}{"animal":"dog","car":"chevy"}
objMerge = objMerge.replace(/\}\{/, ","); // \_ replace with comma for valid JSON
objMerge = JSON.parse(objMerge); // { food: 'pizza', animal: 'dog', car: 'chevy'}
// Of same keys in both objects, the last object's value is retained_/
请注意,在此示例中,“}{”不能出现在字符串中!
我扩展了David Coallier的方法:
增加了合并多个对象的可能性支持深层对象override参数(如果最后一个参数是布尔值,则检测到)
如果覆盖为false,则不会覆盖任何属性,但会添加新的财产。
用法:obj.merge(合并…[,覆盖]);
这是我的代码:
Object.defineProperty(Object.prototype, "merge", {
enumerable: false,
value: function () {
var override = true,
dest = this,
len = arguments.length,
props, merge, i, from;
if (typeof(arguments[arguments.length - 1]) === "boolean") {
override = arguments[arguments.length - 1];
len = arguments.length - 1;
}
for (i = 0; i < len; i++) {
from = arguments[i];
if (from != null) {
Object.getOwnPropertyNames(from).forEach(function (name) {
var descriptor;
// nesting
if ((typeof(dest[name]) === "object" || typeof(dest[name]) === "undefined")
&& typeof(from[name]) === "object") {
// ensure proper types (Array rsp Object)
if (typeof(dest[name]) === "undefined") {
dest[name] = Array.isArray(from[name]) ? [] : {};
}
if (override) {
if (!Array.isArray(dest[name]) && Array.isArray(from[name])) {
dest[name] = [];
}
else if (Array.isArray(dest[name]) && !Array.isArray(from[name])) {
dest[name] = {};
}
}
dest[name].merge(from[name], override);
}
// flat properties
else if ((name in dest && override) || !(name in dest)) {
descriptor = Object.getOwnPropertyDescriptor(from, name);
if (descriptor.configurable) {
Object.defineProperty(dest, name, descriptor);
}
}
});
}
}
return this;
}
});
示例和测试用例:
function clone (obj) {
return JSON.parse(JSON.stringify(obj));
}
var obj = {
name : "trick",
value : "value"
};
var mergeObj = {
name : "truck",
value2 : "value2"
};
var mergeObj2 = {
name : "track",
value : "mergeObj2",
value2 : "value2-mergeObj2",
value3 : "value3"
};
assertTrue("Standard", clone(obj).merge(mergeObj).equals({
name : "truck",
value : "value",
value2 : "value2"
}));
assertTrue("Standard no Override", clone(obj).merge(mergeObj, false).equals({
name : "trick",
value : "value",
value2 : "value2"
}));
assertTrue("Multiple", clone(obj).merge(mergeObj, mergeObj2).equals({
name : "track",
value : "mergeObj2",
value2 : "value2-mergeObj2",
value3 : "value3"
}));
assertTrue("Multiple no Override", clone(obj).merge(mergeObj, mergeObj2, false).equals({
name : "trick",
value : "value",
value2 : "value2",
value3 : "value3"
}));
var deep = {
first : {
name : "trick",
val : "value"
},
second : {
foo : "bar"
}
};
var deepMerge = {
first : {
name : "track",
anotherVal : "wohoo"
},
second : {
foo : "baz",
bar : "bam"
},
v : "on first layer"
};
assertTrue("Deep merges", clone(deep).merge(deepMerge).equals({
first : {
name : "track",
val : "value",
anotherVal : "wohoo"
},
second : {
foo : "baz",
bar : "bam"
},
v : "on first layer"
}));
assertTrue("Deep merges no override", clone(deep).merge(deepMerge, false).equals({
first : {
name : "trick",
val : "value",
anotherVal : "wohoo"
},
second : {
foo : "bar",
bar : "bam"
},
v : "on first layer"
}));
var obj1 = {a: 1, b: "hello"};
obj1.merge({c: 3});
assertTrue(obj1.equals({a: 1, b: "hello", c: 3}));
obj1.merge({a: 2, b: "mom", d: "new property"}, false);
assertTrue(obj1.equals({a: 1, b: "hello", c: 3, d: "new property"}));
var obj2 = {};
obj2.merge({a: 1}, {b: 2}, {a: 3});
assertTrue(obj2.equals({a: 3, b: 2}));
var a = [];
var b = [1, [2, 3], 4];
a.merge(b);
assertEquals(1, a[0]);
assertEquals([2, 3], a[1]);
assertEquals(4, a[2]);
var o1 = {};
var o2 = {a: 1, b: {c: 2}};
var o3 = {d: 3};
o1.merge(o2, o3);
assertTrue(o1.equals({a: 1, b: {c: 2}, d: 3}));
o1.b.c = 99;
assertTrue(o2.equals({a: 1, b: {c: 2}}));
// checking types with arrays and objects
var bo;
a = [];
bo = [1, {0:2, 1:3}, 4];
b = [1, [2, 3], 4];
a.merge(b);
assertTrue("Array stays Array?", Array.isArray(a[1]));
a = [];
a.merge(bo);
assertTrue("Object stays Object?", !Array.isArray(a[1]));
a = [];
a.merge(b);
a.merge(bo);
assertTrue("Object overrides Array", !Array.isArray(a[1]));
a = [];
a.merge(b);
a.merge(bo, false);
assertTrue("Object does not override Array", Array.isArray(a[1]));
a = [];
a.merge(bo);
a.merge(b);
assertTrue("Array overrides Object", Array.isArray(a[1]));
a = [];
a.merge(bo);
a.merge(b, false);
assertTrue("Array does not override Object", !Array.isArray(a[1]));
我的equals方法可以在这里找到:JavaScript中的对象比较