PHP Simple Calculator

After work, write to play.

<?PHP$num 1=$_post[' Num1 ']; $num 2=$_post[' Num2 ']; $yusuan=$_post[' Yusuan ']; $jieguo= 0; Switch($yusuan){             Case' + ':$jieguo=$num 1+$num 2; Break;  Case‘-‘:$jieguo=$num 1-$num 2; Break;  Case‘*‘:$jieguo=$num 1*$num 2; Break;  Case‘/‘:$jieguo=$num 1/$num 2; Break; }    ?> <form action= "" method= "post" > <table align= "Center" border= "1" > <tr> <td><input type= "text" name= "NUM1" value= "<?php Echo$num 1;?> "/></td> <td> <select name=" Yusuan "> <option value= "+" <?phpif($yusuan=="+"){Echo' selected= ' select ';} ?> ">+</option> <option value="-" <?php if ($yusuan= = "-") {echo ' selected= ' select ';} ?> ">-</option> <option value=" * "<?phpif($yusuan=="*"){Echo' selected= ' select ';} ?> ">*</option> <option value="/" <?php if ($yusuan= = "/") {echo ' selected= ' select ';} ?> ">/</option> </select> </td> <td><inpu T type= "text" name= "num2" value= "<?php Echo$num 2;?> "/></td> <td><input type=" Submit "value=" = "/></td> <td& Gt;<input type= "text" name= "Jieguo" value= "<?php Echo$jieguo;? > "/></td> </tr> </table> </form>

PHP Simple Calculator