In ES6, a new form of arrow function was added, which is actually a function;
Here's a brief look at :
<
script
>
let
func
=
canshu
=>
canshu;
console
.
log
(
func
(
3
));
</
script
>
Above we defined a function in the form of an es6 arrow function;
let is equivalent to the previous var, used to define variables, but let has the nature of block-level scope;
func represents the function name;
The equal sign = is followed by our parameters;
After the arrow is our return value;
Compare and see :
<
script
>
//es6 way
let
func
=
canshu
=>
canshu;
console
.
log
(
func
(
3
));
// before our way
function
func
(
canshu
){
return
(canshu);
}
//or write like this
var
func
=
function(
canshu){
return(canshu);
}
</
script>
上面的箭头函数默认的是一个参数的情况,如果我们有多个参数怎么写?
很简单,把参数用小括号括起来就可以了:
<
script>
//es6的方式
let
func
=(
canshu1,
canshu2)
=> canshu1
+canshu2;
console.
log(
func(
3,
2));
</
script>
上面的函数的返回是只有一条语句时的情况,按上面的写法会默认返回,但是函数里面很少只有一个语句,
我们看看多条语句的情况下是如何来写?
<
script>
//es6的方式
let
func
=(
canshu1,
canshu2)
=> {
if(canshu1
>canshu2){
return canshu1;
}
else{
return canshu2;
}
};
console.
log(
func(
3,
8));
</
script>
首先多条语句,需要在箭头函数后面加上 { 语句都写在这里面 }
其次,返回值需要我们显式的写出来,也就是 return + 结果 ;
了解上面的部分就可以基本的使用箭头函数了,更多的详细信息请自行查阅文档;