Question

var array = [
    { name:"test0", value:"0" },
    { name:"test1", value:"1" },
    { name:"test2", value:"2" },
    { name:"test0", value:"3" },
    { name:"test0", value:"4" }
];

如何使用JavaScript中的循环获取与test0关联的所有元素名称的值？

样品输出

{0,3,4}

Answer 1

只需过滤值并映射所需的值即可。

array.filter允许您过滤带有条件的数组的项，因此使用i => i.name === 'test0'将返回一个新数组，其中仅获取名称为'test0'的值。最后，使用map创建一个新数组，其值是所提供的回调函数的结果。因此，使用map(i => i.value)将返回每个（已过滤）对象的属性.value。

如果期望值是数字，请记住将它们转换为整数。

var array = [
    { name:"test0", value:"0" },
    { name:"test1", value:"1" },
    { name:"test2", value:"2" },
    { name:"test0", value:"3" },
    { name:"test0", value:"4" }
];

var res = array.filter(i => i.name === 'test0').map(i => i.value);
console.log(res);

否则，您可以使用reduce一次完成此操作：

var array = [
    { name:"test0", value:"0" },
    { name:"test1", value:"1" },
    { name:"test2", value:"2" },
    { name:"test0", value:"3" },
    { name:"test0", value:"4" }
];

var res = array.reduce((a,b) => {
  return b.name === 'test0' && a.push(+b.value), a;
}, []);
console.log(res);

在最后一个示例中，使用一元运算符（+）将值转换为整数。

最后，根据要求，这是另一种不依赖任何数组原型的方法：

var array = [
    { name:"test0", value:"0" },
    { name:"test1", value:"1" },
    { name:"test2", value:"2" },
    { name:"test0", value:"3" },
    { name:"test0", value:"4" }
];

// init a new empty array.
var res = [];
for (var i = 0; i < array.length; i++) {
  var item = array[i]; // not mandatory but easy enough to read: acquire the current looped value.
  if (item.name === 'test0') { // if the looped item name is 'test0', join the if.
    res.push(Number(item.value)); // if so, push the item's value, and cast it to a number (using Number).
  }
}
console.log(res); // log the result.

Answer 2

您可以使用数组过滤器。 Docs here

const result = array.filter(a=> a.name === "test0");

console.log(result.map(w => w.value));

Answer 3

var array = [
    { name:"test0", value:"0" },
    { name:"test1", value:"1" },
    { name:"test2", value:"2" },
    { name:"test0", value:"3" },
    { name:"test0", value:"4" }
];

var test0 = array.filter(item => item.name == "test0").map(item => item.value);

console.log(test0);

Answer 4

您可以过滤对象并通过映射获得数值。

var array = [{ name: "test0", value: "0" }, { name: "test1", value: "1" }, { name: "test2", value: "2" }, { name: "test0", value: "3" }, { name: "test0", value: "4" }],
    result = array
        .filter(({ name }) => name === 'test0')
        .map(({ value }) => +value);

console.log(result);

Answer 5

	var array = [
		{ name:"test0", value:"0" },
		{ name:"test1", value:"1" },
		{ name:"test2", value:"2" },
		{ name:"test0", value:"3" },
		{ name:"test0", value:"4" }
	];
	var Rs=[];
	for(var i in array){
		if(array[i]["name"]=="test0")
			Rs.push(i);//Rs.push(array[i]["value"]);
	}
	console.log(Rs);

简单的循环就是野兽！

Answer 6

var array = [
    { name:"test0", value:"0" },
    { name:"test1", value:"1" },
    { name:"test2", value:"2" },
    { name:"test0", value:"3" },
    { name:"test0", value:"4" }
];
let output = array.reduce((acc, {name, value}) => {
	if(name === 'test0') {
		return [...acc, value];
	}
	return acc;
}, []);
console.log(output)

Answer 7

create a generic function in which you just need to pass the key value and array and it will filter out the arry on the basic of parameters  

  var array = [
        { name:"test0", value:"0" },
        { name:"test1", value:"1" },
        { name:"test2", value:"2" },
        { name:"test0", value:"3" },
        { name:"test0", value:"4" }
    ];

    function filterList(keyValue, list) {
        let filteredList = [];
        for(let i = 0; i < list.length; i++) {
            if(list[i]["name"] === keyValue) {
                filteredList.push(list[i]["value"]);
            }
        }
        return filteredList;
    }

    console.log(filterList("test0", array));

如何获取与数组中的对象关联的所有值？

7 个答案: