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
**使用Object.assign或排列合并对象很简单。。。操作员**
var obj1={food:“pizza”,car:“ford”}var obj2={animal:“狗”,car:“宝马”}var obj3={a:“a”}var mergedObj=对象赋值(obj1、obj2、obj3)//或使用Spread操作符(…)var mergedObj={…obj1,…obj2,…obj3}console.log(mergedObj);
对象从右向左合并,这意味着与右侧对象具有相同财产的对象将被覆盖。
在此示例中,obj2.car覆盖obj1.car
其他回答
A={a:1,b:function(){alert(9)}}
B={a:2,c:3}
A.merge = function(){for(var i in B){A[i]=B[i]}}
A.merge()
结果是:{a:2,c:3,b:function()}
请注意,underline.js的extend方法在一行中实现了这一点:
_.extend({name : 'moe'}, {age : 50});
=> {name : 'moe', age : 50}
我使用纯JavaScript中的以下内容。它从最右边的参数开始,并将它们组合到第一个参数。没有返回值,只修改了第一个参数,最左边的参数(第一个除外)在财产上具有最高的权重。
var merge = function() {
var il = arguments.length;
for (var i = il - 1; i > 0; --i) {
for (var key in arguments[i]) {
if (arguments[i].hasOwnProperty(key)) {
arguments[0][key] = arguments[i][key];
}
}
}
};
Object.assign(TargetObject, Obj1, Obj2, ...);
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