如何从数组中删除对象? 我希望从someArray中删除包含名称Kristian的对象。例如:
someArray = [{name:"Kristian", lines:"2,5,10"},
{name:"John", lines:"1,19,26,96"}];
我想实现:
someArray = [{name:"John", lines:"1,19,26,96"}];
如何从数组中删除对象? 我希望从someArray中删除包含名称Kristian的对象。例如:
someArray = [{name:"Kristian", lines:"2,5,10"},
{name:"John", lines:"1,19,26,96"}];
我想实现:
someArray = [{name:"John", lines:"1,19,26,96"}];
当前回答
你也可以使用地图功能。
someArray = [{name:"Kristian", lines:"2,5,10"},{name:"John",lines:"1,19,26,96"}];
newArray=[];
someArray.map(function(obj, index){
if(obj.name !== "Kristian"){
newArray.push(obj);
}
});
someArray = newArray;
console.log(someArray);
其他回答
这个怎么样?
$.each(someArray, function(i){
if(someArray[i].name === 'Kristian') {
someArray.splice(i,1);
return false;
}
});
我建议使用lodash.js或sugar.js来完成以下常见任务:
// lodash.js
someArray = _.reject(someArray, function(el) { return el.Name === "Kristian"; });
// sugar.js
someArray.remove(function(el) { return el.Name === "Kristian"; });
在大多数项目中,拥有一组由此类库提供的helper方法是非常有用的。
性能
今天2021.01.27我在Chrome v88, Safari v13.1.2和Firefox v84上对所选解决方案的MacOs HighSierra 10.13.6进行测试。
结果
对于所有浏览器:
当元素不存在时,最快/最快的解决方案:A和B 快速/最快的大数组解决方案:C 当元素存在时,大数组的快速/最快解决方案:H 对于小数组来说是非常缓慢的解:F和G 对于大数组:D, E和F,非常缓慢的解决方案
细节
我执行4个测试用例:
小数组(10个元素)和元素存在-你可以在这里运行它 小数组(10个元素)和元素不存在-你可以在这里运行它 大数组(百万元素)和元素存在-你可以在这里运行它 大数组(百万元素)和元素不存在-你可以在这里运行它
下面的代码片段展示了解决方案之间的差异 一个 B C D E F G H 我
function A(arr, name) { let idx = arr.findIndex(o => o.name==name); if(idx>=0) arr.splice(idx, 1); return arr; } function B(arr, name) { let idx = arr.findIndex(o => o.name==name); return idx<0 ? arr : arr.slice(0,idx).concat(arr.slice(idx+1,arr.length)); } function C(arr, name) { let idx = arr.findIndex(o => o.name==name); delete arr[idx]; return arr; } function D(arr, name) { return arr.filter(el => el.name != name); } function E(arr, name) { let result = []; arr.forEach(o => o.name==name || result.push(o)); return result; } function F(arr, name) { return _.reject(arr, el => el.name == name); } function G(arr, name) { let o = arr.find(o => o.name==name); return _.without(arr,o); } function H(arr, name) { $.each(arr, function(i){ if(arr[i].name === 'Kristian') { arr.splice(i,1); return false; } }); return arr; } function I(arr, name) { return $.grep(arr,o => o.name!=name); } // Test let test1 = [ {name:"Kristian", lines:"2,5,10"}, {name:"John", lines:"1,19,26,96"}, ]; let test2 = [ {name:"John3", lines:"1,19,26,96"}, {name:"Kristian", lines:"2,5,10"}, {name:"John", lines:"1,19,26,96"}, {name:"Joh2", lines:"1,19,26,96"}, ]; let test3 = [ {name:"John3", lines:"1,19,26,96"}, {name:"John", lines:"1,19,26,96"}, {name:"Joh2", lines:"1,19,26,96"}, ]; console.log(` Test1: original array from question Test2: array with more data Test3: array without element which we want to delete `); [A,B,C,D,E,F,G,H,I].forEach(f=> console.log(` Test1 ${f.name}: ${JSON.stringify(f([...test1],"Kristian"))} Test2 ${f.name}: ${JSON.stringify(f([...test2],"Kristian"))} Test3 ${f.name}: ${JSON.stringify(f([...test3],"Kristian"))} `)); <script src="https://code.jquery.com/jquery-3.5.1.min.js" integrity="sha256-9/aliU8dGd2tb6OSsuzixeV4y/faTqgFtohetphbbj0=" crossorigin="anonymous"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js" integrity="sha512-90vH1Z83AJY9DmlWa8WkjkV79yfS2n2Oxhsi2dZbIv0nC4E6m5AbH8Nh156kkM7JePmqD6tcZsfad1ueoaovww==" crossorigin="anonymous"> </script> This shippet only presents functions used in performance tests - it not perform tests itself!
这里是chrome的示例结果
你也可以用一些:
someArray = [{name:"Kristian", lines:"2,5,10"},
{name:"John", lines:"1,19,26,96"}];
someArray.some(item => {
if(item.name === "Kristian") // Case sensitive, will only remove first instance
someArray.splice(someArray.indexOf(item),1)
})
虽然这可能不适合这种情况,我发现前几天,如果你不需要改变数组的大小,你也可以使用delete关键字从数组中删除一个项目。
var myArray = [1,2,3];
delete myArray[1];
console.log(myArray[1]); //undefined
console.log(myArray.length); //3 - doesn't actually shrink the array down