js数组的splice方法_js数组删除某一项

//指定位置删除指定个数元素(多个)
var arr = ['a','b','c','d'];
var res = arr.splice(2,1);
console.log(res); //返回被删除的元素：["c"]
console.log(arr); //修改后的数组：["a", "b", "d"]

//指定位置删除指定个数(0个)
var arr = ['a','b','c','d'];
var res = arr.splice(2,0);
console.log(res); //返回被删除的元素：[]
console.log(arr); //修改后的数组：["a", "b", "c", "d"]

//指定位置删除元素同时插入元素
var arr = ['a','b','c','d'];
var res = arr.splice(2,1,'插入');
console.log(res); //返回被删除的元素：["c"]
console.log(arr); //修改后的数组：["a", "b", "插入", "d"]

delete object.property 
delete object['property']
delete array[index]

//删除对象的某个属性
let obj = {
    name:'alax',
    age:18,
    sex:'男'
}
delete obj.age
console.log(obj) //{name: "alax", sex: "男"}

delete obj['sex']
console.log(obj) //{name: "alax"}

//删除数组中的某一项（不会改变原有数组长度）
let arr =[1,2,3,4]
delete arr[0]
console.log(arr) //[empty, 2, 3, 4]