函数作为其他变量的值。可以直接调用；
1 <!DOCTYPE html> 2 <html lang="zh"> 3 4 <head> 5 <meta charset="UTF-8"> 6 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 7 <meta http-equiv="X-UA-Compatible" content="ie=edge"> 8 <title>Document</title> 9 </head> 10 11 <body> 12 13 <script> 14 15 16 17 function foo(x, y) { 18 if (x > y) { 19 return x; 20 } else { 21 return y; 22 } 23 } 24 25 // 将 foo 函数作为变量 bar 的值 26 var bar = foo; 27 28 console.log(foo(12, 88)) 29 console.log(bar(12, 66)) 30 31 </script> 32 </body> 33 34 </html>