条件控制：if
<?php
function getLevel($score){
if($score>=90){
return "优秀";
}elseif($score>=80){
return "良好";
}elseif($score>=70){
return "中等";
}elseif($score>=60){
return "及格";
}else{
return "差";
}
}
echo getLevel(90);
多分支控制：switch
<?php
function getLevel($score){
switch(intval($score/10)){ //intval()把变量转换成整数类型
case 10:
case 9:
return "优秀";
case 8:
return "良好";
case 7:
return "中等";
case 6:
return "及格";
default:
return "差";
}
}
echo getLevel(90);
Break（终止语句执行）
<?php
function getLevel($score){
$result = "差";
switch($score/10) {
case 10:
case 9:
$result = "优秀";
break;
case 8:
$result = "良好";
break;
case 7:
$result = "中等";
break;
case 6:
$result = "及格";
break;
default:
return "差";
}
return $result;
}
echo getLevel(90);