前言：在项目开发中，经常会遇到多个复杂if else的情况，下面说说这种情况的优化方案。
提前return
让正常流程走主干，非正常流程提前return，去除不必要的else，适用于函数参数校验。
- 优化前
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5if (condition){
doSomething
}else{
if (condition){
doSomething
}else{
return ;
} - 优化后
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4if (!condition){
if (!condition){
return ;
}
doSomething
使用三目运算符
适用于根据条件给变量赋值。
- 优化前
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5if (condition){
$status = 1;
}else{
$status =if (condition){
$status = 1;
}else{
$status = 0;
} - 优化后
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$status = condition ? 1 :$status = condition ? 1 : 0;
合并条件表达式
- 优化前
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9if (condition1){
return true;
}
if (condition2){
return true;
}else{
returnif (condition1){
return true;
}
if (condition2){
return true;
}else{
return false;
} - 优化后
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5if (condition1 || condition2){
return true;
}else{
returnif (condition1 || condition2){
return true;
}else{
return false;
}
使用switch case优化
php8可以使用match表达式
- 优化前
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18class A{
public static function handle(string $act, int $userId){
if ($act == 'sign in') {
self::sign($userId);
} elseif ($act == 'register user') {
self::register($userId);
} elseif ($act == 'change password') {
self::changePwd($userId);
}
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(intclass A{
public static function handle(string $act, int $userId){
if ($act == 'sign in') {
self::sign($userId);
} elseif ($act == 'register user') {
self::register($userId);
} elseif ($act == 'change password') {
self::changePwd($userId);
}
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(int $userId){}
} - 优化后效果：和原来的差不多，每次新增方法后还得修改代码。
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24class A{
public static function handle(string $act, int $userId){
switch ($act) {
case 'sign in':
self::sign($userId);
break;
case 'register user':
self::register($userId);
break;
case 'change password':
self::changePwd($userId);
break;
default:
break;
}
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(intclass A{
public static function handle(string $act, int $userId){
switch ($act) {
case 'sign in':
self::sign($userId);
break;
case 'register user':
self::register($userId);
break;
case 'change password':
self::changePwd($userId);
break;
default:
break;
}
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(int $userId){}
}
使用枚举
- 优化前
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7if ($status == 0){
return '待支付';
}elseif($status == 1){
return '已支付';
}else{
returnif ($status == 0){
return '待支付';
}elseif($status == 1){
return '已支付';
}else{
return '支付失败';
} - 优化后
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7$orderStatus = [
0 => '待支付',
1 => '已支付',
2 => '支付失败',
];
return $orderStatus[$orderStatus = [
0 => '待支付',
1 => '已支付',
2 => '支付失败',
];
return $orderStatus[$status];
表驱动法
- 优化前
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18class A{
public static function handle(string $act, int $userId){
if ($act == 'sign in') {
self::sign($userId);
} elseif ($act == 'register user') {
self::register($userId);
} elseif ($act == 'change password') {
self::changePwd($userId);
}
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(intclass A{
public static function handle(string $act, int $userId){
if ($act == 'sign in') {
self::sign($userId);
} elseif ($act == 'register user') {
self::register($userId);
} elseif ($act == 'change password') {
self::changePwd($userId);
}
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(int $userId){}
} - 优化后效果：新增方法后，只需修改配置项，不用变更其他代码。
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19class A{
private static $acts = [
'sign in' => 'sign',
'register use' => 'register',
'change password' => 'changePwd',
];
public static function handle(string $act, int $userId){
$fun = !empty($act) && isset(self::$acts[$act]) ? self::$acts[$act] : null;
if ($fun) call_user_func($fun, $userId);
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(intclass A{
private static $acts = [
'sign in' => 'sign',
'register use' => 'register',
'change password' => 'changePwd',
];
public static function handle(string $act, int $userId){
$fun = !empty($act) && isset(self::$acts[$act]) ? self::$acts[$act] : null;
if ($fun) call_user_func($fun, $userId);
}
protected static function sign(int $userId){}
protected static function register(int $userId){}
protected static function changePwd(int $userId){}
}
