1.函数参数的默认值
<script>
function fn(x,y=20){
console.log(x,y);
}
fn(10);
</script>
控制台输出结果为:
10 20
2. arguments获取用户输入的所有实参,是一个类数组
<script>
function fn(x,y){
var list = Array.from(arguments);
list.forEach(function(item){
console.log(item);
});
}
fn(10,20,30,40,50);
</script>
控制台输出结果为:
10
20
30
40
50
3.箭头函数
<script>
var fn = () => {
console.log('Hello Vue');
}
fn();
</script>
相当于:
<script>
var fn = function () {
console.log('Hello Vue');
}
fn();
</script>
4.如果函数体只有一句话,可以省略{}
<script>
var fn = () =>console.log('Hello Vue');
fn();
</script>
相当于:
<script>
var fn = () => {
console.log('Hello Vue');
}
fn();
</script>
5.如果函数体只有一句return语句,省略return
<script>
var fn = () => 'Hello Vue';
console.log(fn());
</script>
相当于:
<script>
var fn = () => {
return 'Hello Vue';
}
console.log(fn());
</script>
6.箭头函数,没有了arguments的概念,但有了剩余参数的概念
<script>
var fn = (x,y,...args) => {
console.log(args);
}
fn(1,2,3,4,5);
</script>
控制台输出结果为:
[3, 4, 5]