$$i=1;

$$sum=0;

While($$i<100){

$$sum+=$$i;

$$i+=2;

}

Echo$sum;

phpinfo( );

?>

$$socre=85;

Switch (true){

Case $$socre>90:

$grade='优秀';

Break;

Case $$socre>80:

$$grade='良好';

Break;

Case $$socre>70:

$$grade='中等';

Break;

Case $$socre>60:

$$grade='及格';

Break;

Default:

$grade='不及格';

Break;

}

$$a=5;

$$b=1;

If($$a){

$$b=0;

}else{

$$b=$$a;

}

Echo $b;

浏览器中显示( )。

$$a=5;

$$b="10";

$$b=$$a+$b;