JS Branch Structure Switch--case

Switch...case ... Multiple branches, depending on the condition, select Execute

Syntax:     Switch (expression)        {case-  expression 1:             code snippet 1;
Break             ;          Case expression N:             code snippet N;
             Break
Default
             Default execution code;

Operating mechanism: If a case is found that matches the value of the expression, not only the code under the current cases is executed, but all the code is then triggered!

Break : exits the current structure;

When multiple conditions are common with the same set of execution logic, no break is added;

<! DOCTYPE html>//Please enter a score:            //if the score>=90 output is excellent            //if the score>=80 output is excellent            //if the score>=60 output C            //otherwise output d            varScore = parseint (Prompt ("Please enter fractions"))); Switch(true){                 CaseScore>=90:                 CaseScore>=80: Console.log (Excellent);  Break;  CaseScore>=60: Console.log (C);  Break; default: Console.log (D);  Break; }        </script> </body>
The implementation of the above switch...case can also be implemented using the If...else If...else method, as follows:
<! DOCTYPE html>varScore = parseint (Prompt ("Please enter fractions"))); if(score>=90) {Console.log (A); }Else if(score>=80) {Console.log (B); }Else if(score>=60) {Console.log (C); }Else{Console.log (D); }        </script> </body>
The following examples should be noted below:
Switch...case is congruent = = = strictly equal without automatic type conversion
If Num===1, perform
If num===2, perform
If num===3, perform
<! DOCTYPE html>varNum=parseint (Prompt ("Please select service type"))); Switch(num) { Case1://if Num===1Console.log ("In Balance query");  Break;  Case2://if num===2Console.log ("Withdrawal in progress");  Break;  Case3://if Num===3Console.log ("Transfer in Progress");  Break; default: Console.log ("Exit System");  Break; }        </script> </body>
// Modify: If you remove parseint  Quote ' case ' 1 ' :    case ' 2 ':
The modified code looks like this:
varNum=prompt ("Please select the type of service"); Switch(num) { Case' 1 '://if Num===1Console.log ("In Balance query");  Break;  Case' 2 '://if num===2Console.log ("Withdrawal in progress");  Break;  Case' 3 '://if Num===3Console.log ("Transfer in Progress");  Break; default: Console.log ("Exit System");  Break; }        </script> </body>
JS Branch Structure Switch--case