PHP getting started tutorial-detailed explanation of the operator and control structure process, Getting Started tutorial Operator

PHP getting started tutorial-detailed explanation of the operator and control structure process, Getting Started tutorial Operator

This document describes the operator and control structure of the PHP getting started tutorial. We will share this with you for your reference. The details are as follows:

Demo1.php

<? Php $ username = "chaoyv"; echo "His name is $ username! "; $ Username2 =" Wu zhiran "; echo" His name is $ username2! "; Echo" <br/> "; echo" His name is ". $ username2.", who asked me? \ n. "; Echo" <br/> "; echo" His name is ". $ username2.", who will read this question? \ t water is refreshing and refreshing. "; Echo 'his name is $ username2! '; // Unable to parse $ 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'; // the embodiment of true on the webpage is 1, false: NULL // constant. The required data type is also the same. // $ a ===$ B returns a false, false // echo! ($ A ===$ B); // What does this print? $ 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; // ternary operator // if it is true, the first string is returned as a whole; otherwise, the second string $ sum = $ total> 50? 'Success': 'failed'; echo $ sum;?>

Demo5.php

<? Php // it is best to expose all errors during development. // $ 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 condition judgment statement $ userAge = 25; // The brackets after if are boolean expressions, the returned result is 1 or null // {} BLOCK statement // if ($ userAge> 18) {// echo 'success'; //} // if... Otherwise // if ($ userAge> 18) {// echo 'success'; //} else {// echo 'failed '; /// multiline if ($ userAge <18) {echo '<18';} elseif ($ userAge <30) {echo' <25 ';} else {echo 'passed';}?>

Demo7.php

<? Php // multi-line // break exit problem, which is called exit in the middle. The condition $ weekday = 3; switch ($ weekday) {case 1: echo 'today Monday'; break; case 2: echo 'tuesday '; break; case 3: echo 'wedday'; break; case 4: echo 'thursday'; break; default: echo 'unclear ';}?>

Demo8.php

<? Php // while LOOP // when the expression is determined to be false, exit the loop $ a = 10; while ($ a> 0) {echo $ 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 ++) {//// nested an IF judgment statement in this loop // if ($ I = 5) {// break; // exit the loop halfway //} // echo $ I. '<br/>'; //} // for ($ I = 0; $ I <10; $ I ++) {// nested an IF judgment statement in this loop // if ($ I = 5) {// exit; // exit the entire program //} // echo $ I. '<br/>'; //} // echo 'I will execute'; for ($ I = 0; $ I <10; $ I ++) {// nest an IF judgment statement in this loop if ($ I = 5) {continue; // exit the current loop and continue the next loop OK} echo $ I. '<br/>' ;}?>