| 
														
															@@ -0,0 +1,42 @@ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+<!DOCTYPE html> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+<html lang="en"> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+<head> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    <meta charset="UTF-8"> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    <meta http-equiv="X-UA-Compatible" content="IE=edge"> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    <meta name="viewport" content="width=device-width, initial-scale=1.0"> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    <title>箭头函数应用场景</title> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+</head> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+<body> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    <div style="width:200px;height:200px;background:green;" id="box"></div> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    <script> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+        // 点击div 2s后变颜色 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            let ad = document.getElementById("box"); 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            ad.addEventListener('click',function(){ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                let that = this 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                setTimeout(function(){ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                    //this指window 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                    that.style.background = 'pink' 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                },2000) 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                //箭头 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                setTimeout(()=>{ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                    this.style.background = 'pink' 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                }) 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            }) 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+        //从数组中返回偶数元素 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            const arr = [1,2,4,5,3,344] 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            const result = arr.filter(function(item){ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                if(item % 2 === 0){ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                    return true; 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                }else{ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                    return false; 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+                } 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            }) 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            //箭头 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+            const result = arr.filter(item=>item%2 === 0) 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+        //箭头函数适合与this无关的回调,定时器,数组的方法回调 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+        //不适合与this有关的回调,不适合事件回调,对象的方法 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+ 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+    </script> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+</body> 
														 | 
													
												
											
												
													
														| 
														 | 
														
															 
														 | 
														
														 | 
														
															+</html> 
														 |