Original PHP Tutorial: loop statements

While // while is to first judge the condition, if it is true, it is executed and executed multiple times, knowing that the condition is invalid

While // while is to first judge the condition, if it is true, it is executed and executed multiple times, knowing that the condition is invalid

Syntax:

While (expression)

Execute a statement repeatedly;

 

While (expression ){

Execute this loop body repeatedly

}

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Do-while // do-while is the condition that is first executed and then judged

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For

Syntax:

For (initial activation; conditional expression; increment ){

Loop body

}

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While example:

$ Num = 0;

While ($ num <100 ){

Echo "this is the result of executing the {$ num} output.
";

$ Num ++;

}

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While Example 2: // 100 rows, 10 columns, rows, color-changing tables

Echo'

This is a 1000 grid table. ';

Echo'

$ A = 0;

While ($ a <1000)

{

If ($ a % 20 = 0) {$ bg = '# fff111';} else {$ bg = '# ffff ';}

If ($ a % 10 = 0) {echo'

Echo'

$ A ++;

If ($ a % 10 = 0) {echo'

}

Echo'

'; ';} '; ';}

'. $ .'

';

?>

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For example: // you can write multiple expressions.

For ($ I = 0, $ j = 100; $ I <10 & $ j> 50; $ I ++, $ j-= 10 ){

Echo "this is the result of executing $ j in the first $ I loop.
";

}

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For loop instance // 99 multiplication table

For ($ I = 1; $ I <= 9; $ I ++ ){

For ($ j = 1; $ j <= $ I; $ j ++ ){

Echo "{$ j} * {$ I} =". $ I * $ j .'';

}

Echo'
';

}

?>

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Several loop-related statements

Break; // skip loop

Continue; // jumps out of this loop and does not affect other loops.

Exit;

Return;

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Example of break and continue

For ($ I = 0; I I <100; $ I ++ ){

If ($ I = 50)

Break;

Echo "$ I ###################
";

}

For ($ I = 0; I I <100; $ I ++ ){

If ($ I % 3 = 0)

Continue;

Echo "$ I ###################
";

}

?>