Example of PHP loop structure explaining

Example of PHP loop structure explaining _php example

Last Update:2017-01-19 Source: Internet

Author: User

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For Loop statement

Print Pyramid

The Complete pyramid

Copy Code code as follows:

Print Pyramid
$n = 25;
for ($i =1; $i <= $n; $i + +) {
Space loop
For ($k =1 $k <= $n-$i; $k + +) {
Echo ';
}
Character Loops
for ($j =1; $j <= $i *2-1; $j + +) {

if ($i ==1 | | $i = = $n) {
echo '. ';
}
else{
if ($j ==1 | | $j = = $i *2-1) {
echo '. ';
}else{
Echo ';
}
}
}
/*
For ($j =1 $j <= ($i-1) *2+1; $j + +) {
echo '. ';
}*/
Echo ' <br/> ';

}

Switch statement:

Copy Code code as follows:

/* $a = "1";
Switch ($a) {
Case 1:
echo $a;
Break

Default
echo "Error";
Break
}
Automatically convert strings and numbers

Processing when a Boolean value is encountered in a switch selection statement:

Copy Code code as follows:

$b =true;
Switch ($b) {
Case false:
echo "Mismatch";
Break
A value that is not false can be true-----an automatic conversion type
Case "1":
echo "Successful Match";
Break
Default
echo "Ko";
}
1.default statements are executed regardless of order, and if no other case is matched, the default statement is executed
2. If there is no break statement, the result of the next case will be output until there is a break.

While loops and do. While loop:

Copy Code code as follows:

/*while Cycle
$i = 0;
while ($i <10) {
echo "paxster<br>". $i;
$i + +;
}
Do.. While Loop--------perform a second judgment first, execute at least once
/* $do = 0;
do{
Echo ' <br/>paxster ';
$do = $do +1;
}while ($do <8);

The combination of the while loop and the switch selection statement:

Constant:

Copy Code code as follows:

Two methods of defining constants-----
Define (' TAX ', 200);
Echo TAX;

Const TAB=100;
Echo Tab;

To write a simple calculator:

Step1: Writing Input interface

Copy Code code as follows:

Step2: Write Calculation background code

Copy Code code as follows:

<?php
$num 1=$_request[' NUM1 '];
$num 2=$_request[' num2 '];

$operation =$_request[' operation '];
$res = 0;

Switch ($operation) {
Case ' + ':
$res = $num 1+ $num 2;
Break
Case '-':
$res = $num 1-$num 2;
Break
Case ' * ':
$res = $num 1* $num 2;
Break
Case '/':
$res = $num 1/$num 2;
Break
Default
echo ' input error ';
}

Echo ' result is '. $res;
?>

Continue statement: Skips the code following this loop. You can specify that you want to jump out of the specified number of layers, such as continue 2, to jump out of two layers, similar to break 2;

Goto statement: Like the C language, jump to the tagged code, the middle of the code will not be executed, directly ignored.

Copy Code code as follows:

Goto statement
I only perform one time
For ($i =0, $j =50 $i <100; $i + +) {
while ($j-) {
if ($j ==17) goto end;
}
}
Echo ' i= $i ';
End
Echo ' i= '. $i. ' j= '. $j;

Keep it simple,keep it clear.--paxster

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