Execution function of the expression immediately

 

 

. 1    < Script > 
2  
. 3          // function expression (Immediately-invoked function expression, IIFE ) immediate execution is also called self-executing function. 
. 4  
. 5          // most common writing a: 
. 6          // (function foo () { 
. 7          //      the console.log ( 'foo') 
. 8          // }) () 
. 9  
10          // most common writing II: 
11          // (function bar () { 
12 is          //      the console.log ( 'bar') 
13 is          // } ()) 
14  
15          // two wording not used: 
16          // + Fun function () { 
. 17          //     console.log('fun')
18         // }()
19 
20         -function xxx () {
21             console.log('xxx')
22         }()
23 
24     </script>