Chapter 3 of basic PHP syntax-process control

I. Condition Statement 1. if statement syntax: if (condition statement 1) for example $ a $ B or $ a & gt; $ B {command executed when Condition Statement 1 is met, such as echo & quot; a is greater than B & quot;} elseif (condition statement 2) for example, $ a & lt; 0 or $ B & lt; 0 {command executed when condition statement 2 is met, for example, echo & quot; because a or...

 

I. Condition Statement

 

1. if statement syntax:

 

If (condition 1) for example $ a = $ B or $ a> $ B

 

{

 

Command executed when Condition 1 is met, such as echo "a is greater than B ";

 

}

 

Elseif (condition statement 2) for example, $ a <0 or $ B <0

 

{

 

Command executed when condition 2 is met, such as echo "because a or B is less than 0, beyond the optional range ";

 

}

 

Else does not need to be connected. the meaning of the branch is that when neither condition 1 nor condition 2 is met

 

{

 

Executed when neither condition 1 nor condition 2 is met. for example, echo "Your input is empty. please enter again ";

 

}

 

$ B) {echo "a> B";} elseif ($ a <$ B) {echo" Output result a> B

 

Instance 2

 

= 60 & $ secore <70) {echo "your score has passed";} elseif ($ secore >=70 & $ secore <80) {echo "your score is good";} elseif ($ secore >=80 & $ secore <90) {echo "your score is good ";} elseif ($ secore >=90 & $ secore <= 100) {echo "your excellent score";} elseif ($ secore> 100 | $ secore <0) {echo "the score you entered is invalid";} else {echo "your score failed. please continue to work." ;}?> Output result: Your score is excellent.

 

(2) switch statement syntax

 

Switch (condition variable) for example: $

 

{

 

Case condition variable conditions such as $ a> 0: executed when the conditions are met, such as echo a> 0; break;

 

Case condition variable conditions such as $ a <0: executed when the condition is met, such as echo a <0; break;

 

Default: output when none of the preceding conditions are met. for example, echo "a and B are invalid ";

 

}

 

= 60 & $ secore <70: $ pj = "your score has passed"; break; case $ secore> = 70 & $ secore <80: $ pj = "your score is good"; break; case $ secore >=80 & $ secore <90: $ pj = "your score is good"; break; case $ secore> = 90 & $ secore <= 100: $ pj = "your excellent performance"; break; case $ secore <0 | $ secore> 100: $ pj = "your score is invalid"; break; default: $ pj = "your score Fails. continue to work." ;}echo $ pj;?> Output result: Your score is excellent.

 

(3) operator syntax

 

Echo (condition, for example: $ a> $ B )? If the condition is true, the statement "a> B": if the condition is not true,"

 

$ B )? "A> B":" II. Process control statement

 

Loop statement

 

1. for statement syntax

 

For ($ variable name = 0; $ array name

 

{

 

Echo $ array name [$ variable name];

 

}

 

Output result: Zhang Chao, Qiao Bin, Chen Wei, Zhao Yongfeng

 

2. while statement syntax

 

$ Variable name = 0

 

While ($ variable name

 

{

 

Echo $ array name [$ variable name];

 

$ Variable name ++

 

}

 

Output result: Zhang Chao, Qiao Bin, Chen Wei, Zhao Yongfeng

 

3. foreach loop syntax

 

Foreach ($ variable name as $ variable rename)

 

{

 

Echo $ variable rename;

 

}

 

Output result: Zhang Chao, Qiao Bin, Chen Wei, Zhao Yongfeng

 

This article is from the "PHP study notes" blog