Implementation of PHP Basic Learning Process Control

PHP has three major process controls: sequential control, branch control, and cyclic control.

1. Sequential Control: YesProgramPerform the preceding steps in sequence.

2. Branch Control: the program can be executed selectively. It can also be divided into single branch, multiple branch, and multiple branch.

A. Single Branch: basic syntax structure:

If (conditional expression ){

Statement;

//.....;

} Tip:The conditional expression is true or false no matter how complex it is;

Eg:

A = 11;

If (A> 10 ){

Echo "A> 10 ";

}

B. Multi-branch: basic syntax:

If (conditional expression ){

Statement;

//.....;

} Else {

Statement;

//.....;

}

C. Multiple branches: basic syntax:

If (conditional expression ){

Statement; n statements;

} Else if (conditional expression ){

Statement; n statements;

} Elseif (conditional expression ){

Statement; n statements;

} Eles {

Statement; n statements;

} Tip:1. Else if can have one or more. 2. The last else can have no

D. Switch branch statement

Switch (expression ){

Case constant 1:

Statement; n statements;

Break;

Case constant 2:

Statement; n statements;

Break;

Case constant 3:

Statement; n statements;

Break;

Default:

Statement; n statements;

Break;

} Note:

1. One or more case statements 2. defaul statement can be absent (based on your own)CodeBusiness Logic) 3. Generally, after a case statement, a break is required to exit the switch statement. 4. Constant type (INT, float, String, Boolean)

Important:The program is first configured in the order of case. If none of them match, the program executes the content of the default statement until it encounters a break and then exits the switch;

If and switch branch comparison:

If is used to determine a certain range, and switch is used to determine a point, we can select them as follows:

Application Scenario: When the branches are just a few points (for example, to determine the direction of the tank), swtich should be used. If your branches are in several regionsIf