PHPの基本演算子と制御構造プロセスのコード例

<?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 &#39;His name is $username2 ! &#39;;//无法解析 $username2
?>

<?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
?>

<?php
// $a = 5;
// $b = &#39;5&#39;;
// //在网页上（真true）的体现是1，假的体现是空
// //恒等必须数据类型也一样
// //$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;
?>

<?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?&#39;成功&#39;:&#39;失败&#39;;
  echo $sum;
?>