我知道以前有人问过类似的问题,但这个问题有点不同。我有一个未命名对象数组,其中包含一个命名对象数组,我需要获取“名称”为“字符串 1”的对象。这是一个示例数组。
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
更新:我应该早点说这个,但是一旦我找到它,我想用一个编辑过的对象替换它。
我知道以前有人问过类似的问题,但这个问题有点不同。我有一个未命名对象数组,其中包含一个命名对象数组,我需要获取“名称”为“字符串 1”的对象。这是一个示例数组。
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
更新:我应该早点说这个,但是一旦我找到它,我想用一个编辑过的对象替换它。
let arr = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
let obj = arr.find(o => o.name === 'string 1');
console.log(obj);
let arr = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
let obj = arr.find((o, i) => {
if (o.name === 'string 1') {
arr[i] = { name: 'new string', value: 'this', other: 'that' };
return true; // stop searching
}
});
console.log(arr);
您可以遍历数组并测试该属性:
function search(nameKey, myArray){
for (var i=0; i < myArray.length; i++) {
if (myArray[i].name === nameKey) {
return myArray[i];
}
}
}
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
var resultObject = search("string 1", array);
在ES6中你可以Array.prototype.find(predicate, thisArg?)
这样使用:
array.find(x => x.name === 'string 1')
http://exploringjs.com/es6/ch_arrays.html#_searching-for-array-elements https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/find
然后替换所述对象(并使用另一种很酷的ES6方法fill
),您可以执行以下操作:
let obj = array.find(x => x.name === 'string 1');
let index = array.indexOf(obj);
array.fill(obj.name='some new string', index, index++);
根据 ECMAScript 6,您可以使用该findIndex
函数。
array[array.findIndex(x => x.name == 'string 1')]
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
var foundValue = array.filter(obj=>obj.name==='string 1');
console.log(foundValue);
考虑到您有以下代码段:
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
您可以使用以下功能来搜索项目
const search = what => array.find(element => element.name === what);
您可以检查是否找到了该项目。
if (search("string 1")) {
console.log(search.value, search.other);
} else {
console.log('No result found');
}
使用 foreach:
let itemYouWant = null;
array.forEach((item) => {
if (item.name === 'string 1') {
itemYouWant = item;
}
});
console.log(itemYouWant);
或者使用地图更好:
const itemYouWant = array.map((item) => {
if (item.name === 'string 1') {
return item;
}
return null;
});
console.log(itemYouWant);
要么使用一个简单的for
循环:
var result = null;
for (var i = 0; i < array.length; i++) {
if (array[i].name === "string 1") {
result = array[i];
break;
}
}
或者,如果可以,也就是说,如果您的浏览器支持它,请使用Array.filter
,这更简洁:
var result = array.filter(function (obj) {
return obj.name === "string 1";
})[0];
使用underscore.js
findWhere 方法:
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
var result = _.findWhere(array, {name: 'string 1'});
console.log(result.name);
一行回答。您可以使用过滤功能来获得结果。
var array = [
{ name:"string 1", value:"this", other: "that" },
{ name:"string 2", value:"this", other: "that" }
];
console.log(array.filter(function(arr){return arr.name == 'string 1'})[0]);
我将 prop 添加为参数,以使其更通用和可重用
/**
* Represents a search trough an array.
* @function search
* @param {Array} array - The array you wanna search trough
* @param {string} key - The key to search for
* @param {string} [prop] - The property name to find it in
*/
function search(array, key, prop){
// Optional, but fallback to key['name'] if not selected
prop = (typeof prop === 'undefined') ? 'name' : prop;
for (var i=0; i < array.length; i++) {
if (array[i][prop] === key) {
return array[i];
}
}
}
用法:
var array = [
{
name:'string 1',
value:'this',
other: 'that'
},
{
name:'string 2',
value:'this',
other: 'that'
}
];
search(array, 'string 1');
// or for other cases where the prop isn't 'name'
// ex: prop name id
search(array, 'string 1', 'id');
摩卡测试:
var assert = require('chai').assert;
describe('Search', function() {
var testArray = [
{
name: 'string 1',
value: 'this',
other: 'that'
},
{
name: 'string 2',
value: 'new',
other: 'that'
}
];
it('should return the object that match the search', function () {
var name1 = search(testArray, 'string 1');
var name2 = search(testArray, 'string 2');
assert.equal(name1, testArray[0]);
assert.equal(name2, testArray[1]);
var value1 = search(testArray, 'this', 'value');
var value2 = search(testArray, 'new', 'value');
assert.equal(value1, testArray[0]);
assert.equal(value2, testArray[1]);
});
it('should return undefined becuase non of the objects in the array have that value', function () {
var findNonExistingObj = search(testArray, 'string 3');
assert.equal(findNonExistingObj, undefined);
});
it('should return undefined becuase our array of objects dont have ids', function () {
var findById = search(testArray, 'string 1', 'id');
assert.equal(findById, undefined);
});
});
测试结果:
Search
✓ should return the object that match the search
✓ should return undefined becuase non of the objects in the array have that value
✓ should return undefined becuase our array of objects dont have ids
3 passing (12ms)
如果您想了解更多为什么这是不好的做法,请参阅这篇文章:
进行数组搜索的原型版本:
Array.prototype.search = function(key, prop){
for (var i=0; i < this.length; i++) {
if (this[i][prop] === key) {
return this[i];
}
}
}
用法:
var array = [
{ name:'string 1', value:'this', other: 'that' },
{ name:'string 2', value:'this', other: 'that' }
];
array.search('string 1', 'name');
你可以用一个简单的循环来做到这一点:
var obj = null;
for (var i = 0; i < array.length; i++) {
if (array[i].name == "string 1") {
obj = array[i];
break;
}
}
另一种方法(帮助@NullUserException 和@Wexoni 的评论)是在数组中检索对象的索引,然后从那里开始:
var index = array.map(function(obj){ return obj.name; }).indexOf('name-I-am-looking-for');
// Then we can access it to do whatever we want
array[index] = {name: 'newName', value: 'that', other: 'rocks'};
与以前的答案类似,我使用了以下内容:
Array.prototype.getIemtByParam = function(paramPair) {
var key = Object.keys(paramPair)[0];
return this.find(function(item){return ((item[key] == paramPair[key]) ? true: false)});
}
用法:
myArray.getIemtByParam(
{name: 'Sasha'}
);
这是搜索和替换的解决方案
function searchAndUpdate(name,replace){
var obj = array.filter(function ( obj ) {
return obj.name === name;
})[0];
obj.name = replace;
}
searchAndUpdate("string 2","New String 2");
您是否在对象列表中的项目中寻找通用搜索(过滤器)而不指定项目键
输入
var productList = [{category: 'Sporting Goods', price: '$49.99', stocked: true, name: 'Football'}, {category: 'Sporting Goods', price: '$9.99', stocked: true, name: 'Baseball'}, {category: 'Sporting Goods', price: '$29.99', stocked: false, name: 'Basketball'}, {category: 'Electronics', price: '$99.99', stocked: true, name: 'iPod Touch'}, {category: 'Electronics', price: '$399.99', stocked: false, name: 'iPhone 5'}, {category: 'Electronics', price: '$199.99', stocked: true, name: 'Nexus 7'}]
function customFilter(objList, text){
if(undefined === text || text === '' ) return objList;
return objList.filter(product => {
let flag;
for(let prop in product){
flag = false;
flag = product[prop].toString().indexOf(text) > -1;
if(flag)
break;
}
return flag;
});}
执行
customFilter(productList, '$9');
如果您使用 jQuery,请尝试 $.grep()。
您可以使用来自 npm的查询对象。您可以使用过滤器搜索对象数组。
const queryable = require('query-objects');
const users = [
{
firstName: 'George',
lastName: 'Eracleous',
age: 28
},
{
firstName: 'Erica',
lastName: 'Archer',
age: 50
},
{
firstName: 'Leo',
lastName: 'Andrews',
age: 20
}
];
const filters = [
{
field: 'age',
value: 30,
operator: 'lt'
},
{
field: 'firstName',
value: 'Erica',
operator: 'equals'
}
];
// Filter all users that are less than 30 years old AND their first name is Erica
const res = queryable(users).and(filters);
// Filter all users that are less than 30 years old OR their first name is Erica
const res = queryable(users).or(filters);
function getValue(){
for(var i = 0 ; i< array.length; i++){
var obj = array[i];
var arr = array["types"];
for(var j = 0; j<arr.length;j++ ){
if(arr[j] == "value"){
return obj;
}
}
}
}
这个答案适用于 typescript / Angular 2、4、5+
我在上面的@rujmah 答案的帮助下得到了这个答案。他的回答带来了数组计数......然后找到该值并将其替换为另一个值......
这个答案所做的只是获取可能通过另一个模块/组件在另一个变量中设置的数组名称......在这种情况下,我构建的数组有一个 css 名称,即stay-dates。所以它所做的是提取该名称,然后允许我将其设置为另一个变量并像这样使用它。就我而言,它是一个 html css 类。
let obj = this.highlightDays.find(x => x.css);
let index = this.highlightDays.indexOf(obj);
console.log('here we see what hightlightdays is ', obj.css);
let dayCss = obj.css;