Switch Branch statement

Description: Executes different code according to the different values of a variable.

Syntax structure:

Switch (variable)

{

Case value 1:

Code 1;

Break

Case Value 2:

Code 2;

Break

Case Value 3:

Code 3;

Break

Default

If none of the above conditions are met, execute the code;

}

Switch Structure Description:

Switch, case, break, and default are all system keywords and must all be lowercase.

Switch parentheses (): Parentheses are typically a variable name, and this variable may have different values.

The value of each case, which is compared to the value of the variable, executes the code after it, if it is consistent.

All case is a "or" relationship, and only one case at a time satisfies the condition.

After the code in each case executes, it must end with the break statement, and after the end, the program will jump to the switch end brace and run.

If you do not write a break statement, all of the following case statements will be executed again.

Example: Output today is the day of the week

/*

(1) Create a DateTime object with a lot of information: hours, minutes, seconds, year, month, day, week

(2) Remove the day of the week value from the Date object

(3) The weekday value (0-6) to output the day of the week in Chinese

*/

(1) Create a System datetime object, where date () is a system function and the first letter is capitalized

var today = new Date ();

(2) Remove the week value from the Date object

var week = Today.getday (); Returns 0-6, 0 for Sunday

(3) Use switch to output the day of the week

var str;

Switch (week)

{

Case 1:

str = "one";

Break

Case 2:

str = "two";

Break

Case 3:

str = "three";

Break

Case 4:

str = "four";

Break

Case 5:

str = "Five";

Break

Case 6:

str = "Six";

Break

Default

str = "Day";

}

(4) Output results

document.write ("Today is the Week" +STR)

if Multi-conditional judgment and Switch the Difference

The condition in the if is generally a range (a>100), and the condition in switch is generally a different value for a variable.

Switch Branch statement