Implementation of PHP basic learning-process control analysis-PHP Tutorial

PHP basic learning: Process control implementation analysis. PHP has three major process controls: sequential control, branch control, and cyclic control. 1. sequential control: it refers to the execution of programs in sequence from above to the next step. 2. branch control: PHP has three major process control options: sequential control, branch control, and cyclic control.

1. sequential control: it refers to the execution of programs in sequence from above to the next step.

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 statements are optional (based on the business logic of your code) 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

Http://www.bkjia.com/PHPjc/326903.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/326903.htmlTechArticlePHP has three major process control: sequential control, branch control, cycle control. 1. sequential control: it refers to the execution of programs in sequence from above to the next step. 2. branch control: Select a program...