<?php

    //插入字符串
    //1.双引号可以解析字符串中的变量：但是前后不能跟中文符号
    $username = "gaoxiong";
    echo "my name is $username";//my name is gaoxiong
    echo "<br>";
    echo "my name is $username，";//my name is
    echo "<br>";

    //2. <br>是网页字符换行，/n是源代码换行

    //3.单引号不能解析变量，单引号速度比双引号好
    echo "my name is {$username}";
    echo "<br>";
    echo 'my name is $username';
?>