Functions and arrow functions

function

One 、  The function classification ：
            1、 With parameters There is a return var x=string.split(',');
            2、 No parameter There is a return var x=string.trim();
            3、 With parameters No return forEach(function(){})
            4、 No parameter No return No,

Two 、 The return value of the function

The function of return value is ： Return to superior caller

3、 ... and 、 Maximum and minimum

var x = [2, 5, 8, 9, 22, 3, 3, 44, 24, 545];
console.log(Math.max(...x));
console.log(Math.min(...x));

Four 、 

Arrow function  

One 、 Anonymous functions :

1、 Execute now ;2、 Method parameter , Event callback

            (function() {
				console.log(' Execute anonymous functions now ');
			})();
			~function() {
				console.log(' Execute anonymous functions now ');
			}();
			!function() {
				console.log(' Execute anonymous functions now ');
			}();

  Two 、 Click on

        document.body.onclick=function(){
				console.log(' Click event ！！');
			}
			var x=[];
			x.forEach(function(){
				
			})

3、 ... and 、  Arrow function Anonymous function Interleave

            (()=>console.log(' Arrow function '))();
			(a=>console.log('a:',a))(5);
			((a,b)=>console.log('a:',a,'b',b))(5,7);
			var x=(()=>{return 'qiku';})();
			var x=(()=>'qiku')();
			console.log(x)

Four 、 data

            var obj={
				name:' Zhang San ',
				birth:'2002-9-8 15:33:22',
				getAage:function(){
					console.log(' Of external functions ：',this.name);
					(()=>{
						console.log(' Of internal functions ：',this.name);
					})();
				}
			}
			obj.getAage();

5、 ... and 、 Button event

            document.querySelector('button').onclick=()=>{
				console.log('onclick:',this);
			}
			document.querySelector('button').onclick=function(){
				console.log('onclick:',this);
			}