JS 删除数组中某个元素

//删除红色的元素  splice（下标，长度）

var arr = ['a','b','c','d'];

arr.splice(1,1);

console.log(arr); 

//['a','c','d']; 

var arr2 = ['a','b','c','d']

arr2.splice(1,2);

console.log(arr2);

//['a','d']