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This article describes the operator and control structure process of PHP introductory tutorial with examples. Share it with everyone for your reference, the details are as follows:
Demo1.php
<?php $username = "chaoyv"; echo "His name is $username !"; $username2 = "吴者然"; echo "His name is $username2 ! "; echo "<br/>"; echo "His name is ".$username2.",阅谁问君诵,\n水落清香浮。"; echo "<br/>"; echo "His name is ".$username2.",阅谁问君诵,\t水落清香浮。"; echo 'His name is $username2 ! ';//无法解析 $username2 ?>
Demo2.php
<?php $a = 5; $b = 6; // $c = $a + $b; // echo $c; // $a += $b;//$a=$a+$b; // echo $a; // $a=++$b;//$b=$b+1 // echo $a; //7 // echo $b; //7 $a=$b++; echo $a; //6 echo $b; //7 ?>
Demo3.php
<?php // $a = 5; // $b = '5'; // //在网页上(真true)的体现是1,假的体现是空 // //恒等必须数据类型也一样 // //$a === $b 返回的是一个假,false // echo !($a===$b); //这个会打印出什么呢? $a = 5; $b = 5; $c = ($a ==$b); //echo $c; $d = 8; $e = 7; $f = ($d ==$e); //echo $c&&$f; echo $c||$f; ?>
Demo4.php
<?php $total = 80; //三元运算符 //如果判断为真true,那么整体返回第一个字符串,否则返回第二个字符串 $sum = $total>50?'成功':'失败'; echo $sum; ?>
Demo5.php
<?php //在开发过程中,最好将错误都暴露出来。 //$a = 100/0; Warning: Division by zero in C:\AppServ\www\Basic3\Demo5.php on line 2 $a = @(100/0); echo $a; ?>
Demo6.php
<?php //if 条件判断语句 $userAge = 25; //if 后面的括号是布尔表达式,返回的结果是1或者空 //{}块语句 // if($userAge>18){ // echo '成功'; // } //如果。。。否则 // if($userAge>18){ // echo '成功'; // }else{ // echo '失败'; // } //多重线路 if($userAge<18){ echo '<18'; }elseif ($userAge<30){ echo '<25'; }else{ echo '通过'; } ?>
Demo7.php
<?php //多重线路 //break退出问题,叫做中途退出这个条件判断 $weekday = 3; switch ($weekday){ case 1: echo '今天星期一'; break; case 2: echo '今天星期二'; break; case 3: echo '今天星期三'; break; case 4: echo '今天星期四'; break; default: echo '不清楚'; } ?>
Demo8.php
<?php //while 循环 //当判断表达式为假的时候,退出循环 $a = 10; while ($a > 0){ echo $a; $a--; echo '<br/>'; } ?>
Demo9.php
<?php //for for($a=10;$a>0;$a--){ echo $a; echo '<br/>'; } ?>
Demo10.php
<?php //do while $a = 10; do{ echo $a; echo '<br/>'; $a--; }while($a>0); ?>
Demo11.php
<?php // for($i = 0;$i<10;$i++){ // //在这个循环里面嵌套一个 IF 判断语句 // if($i==5){ // break;//中途退出循环 // } // echo $i.'<br/>'; // } // for($i = 0;$i<10;$i++){ // //在这个循环里面嵌套一个 IF 判断语句 // if($i==5){ // exit;//退出整个程序 // } // echo $i.'<br/>'; // } // echo '我还会执行的'; for($i = 0;$i<10;$i++){ //在这个循环里面嵌套一个 IF 判断语句 if($i==5){ continue;//退出当前本次循环,并且继续下次循环 OK } echo $i.'<br/>'; } ?>
I hope this article will be helpful to everyone in PHP programming.
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