Question

var foo = [{ bar: 1, baz: [1,2,3] }, { bar: 2, baz: [4,5,6] }];

var filtered = $.grep(foo, function(v){
    return v.bar === 1;
});

console.log(filtered);

http://jsfiddle.net/98EsQ/

有没有办法在不创建新数组和/或对象的情况下修改某个对象属性（比如我上面过滤的属性）？

期望的结果：[{ bar: 1, baz: [11,22,33] }, { bar: 2, baz: [4,5,6] }]

Answer 1

当然，只需改变它：

使用jQuery的$.each：

$.each(foo, function() {
    if (this.bar === 1) {
        this.baz[0] = 11;
        this.baz[1] = 22;
        this.baz[2] = 33;
        // Or: `this.baz = [11, 22, 33];`
    }
});

使用ES5的forEach：

foo.forEach(function(obj) {
    if (obj.bar === 1) {
        obj.baz[0] = 11;
        obj.baz[1] = 22;
        obj.baz[2] = 33;
        // Or: `obj.baz = [11, 22, 33];`
    }
});

...或者你有other looping options in this other SO answer。

Answer 2

.map和 spread （...）运算符

var result = foo.map(el => el.bar == 1 ? {...el, baz: [11,22,33]} : el);

Answer 3

没有jQuery和向后兼容性

for (var i = 0; i < foo.length; i++) {
    if (foo[i].bar === 1) {
        foo[i].baz = [11,12,13];
    }
}

Answer 4

您可以使用find并更改其属性。

let foo = [{ bar: 1, baz: [1,2,3] }, { bar: 2, baz: [4,5,6] }];

let obj = foo.find(f=>f.bar==1);
if(obj)
  obj.baz=[2,3,4];
console.log(foo);

Answer 5

我们也可以通过使用Array的map函数来实现这个目的：

 foo.map((obj) => {
   if(obj.bar == 1){
     obj.baz[0] = 11;
     obj.baz[1] = 22;
     obj.baz[2] = 33;
   }
 })

Answer 6

$.each(foo,function(index,value)
{
    if(this.bar==1)
    {
this.baz[0] = 11;
        this.baz[1] = 22;
        this.baz[2] = 33;
    }

});

但是for循环比$ .each快，所以你可以尝试使用

for(var i=0; i <foo.length; i++)
{

if(foo[i].bar==1)
{
//change the code
}
}

Answer 7

但是在选择任何一种提及的技术之前，请记住与每种方法相关的性能挑战。

Object iterate For-In, average: ~240 microseconds.

Object iterate Keys For Each, average: ~294 microseconds.

Object iterate Entries For-Of, average: ~535 microseconds.

参考-3 JavaScript Performance Mistakes You Should Stop Doing

Answer 8

您可以使用简单的for循环来修改数组

var foo = [{ bar: 1, baz: [1,2,3] }, { bar: 2, baz: [4,5,6] }];
for(i = 0;i < foo.length;i++){
  //Here your confition for which item you went to edit
	if(foo[i].bar == 1){
    //Here you logic for update property
		foo[i].baz= [1,11,22]
	}
}
console.log(foo);

Answer 9

您可以利用javascript的过滤器功能。

obj = [
    {inActive:false, id:1},
    {inActive:false, id:2},
    {inActive:false, id: 3}
];
let nObj = obj.filter(ele => {
    ele.inActive = true;
    return ele;
});

console.log(nObj);

Answer 10

您可以玩：

const tasks = [ { id: 1, done: false }, { id: 2, done: false } ]
const completed_task = { id: 1, done: true }

const markCompleted = (tasks, task) => {
  const index = tasks.findIndex(t => t.id === task.id);
  tasks.splice(index, 1);
  tasks.push(task);
  return tasks;
}

console.log(tasks)
console.log(markCompleted(tasks, completed_task))

编辑

为避免索引更改：

const markCompleted = (tasks, task) => {
      const index = tasks.findIndex(t => t.id === task.id);
      tasks[index] = task;
      return tasks;
    }

Answer 11

    const objArr = [
        {prop1: 'value1', prop2: 'value11'},
        {prop1: 'value2', prop2: 'value22'},
        {prop1: 'value3', prop2: 'option33'},
        {prop1: 'value4', prop2: 'option44'}
    ]

    const newObjArr = objArr.map(obj => {
            if (['value1', 'value2'].includes(obj.prop1)) {
                return {...obj, prop1: 'newValue'}
            }
            return obj
        }
    )
    
    // const responseGotten = [
    //     { prop1: 'newValue', prop2: 'value11' },
    //     { prop1: 'newValue', prop2: 'value22' },
    //     { prop1: 'value3', prop2: 'option33' },
    //     { prop1: 'value4', prop2: 'option44' }
    // ]

修改对象数组中的对象属性

11 个答案: