小编Jim*_*imF的帖子

为什么第一个函数不像第二个函数那样修改原始数组？

var a= [3, 4, 5];
function doesNothing(a) {
    a=[1,1,1];
}

function doesSomething(a) {
    a.push(6);
}

doesNothing(a);
console.log(a);     // [3,4,5] not [1,1,1]
doesSomething(a);
console.log(a);     //[3,4,5,6]