Replace Nested If Else Statement with Array

The use of Early return and Array Approach will be considered

Nested if else

I am very sure we have either written or seen such nested code.

It isn't pleasant to look at.

public function checkData($var){
    if (isset($var)){
          if ($var==1){
              return 'one';
          }
          elseif($var==2){
              return 'two';
          }
          elseif($var==3){
              return 'three';
          }
          elseif($var==4){
              return 'four';
          }    
    }
    else{
     return 'null';
    }

}

We can make it better

Early Return

public function checkData($var){
    if (!isset($var)){
        return 'null';
    }
    if ($var==1){
        return 'one';
    }
    if($var==2){
        return 'two';
    }
    if($var==3){
        return 'three';
    }
    if($var==4){
        return 'four';
    }
}

Array Approach

public function checkData($var){
    $array = [
    '1'=>'one',
    '2'=>'two',
    '3'=>'three',
    '4'=>'four',
    ];
    return $array[$var] ?? 'null'; 
}

The array approach is easy to update and easier to understand as compared to the nested If Else.

The early return also works very fine!

The Array approach can also be used for methods.

Early return Method calling

public function checkData($var){
    if (!isset($var)){
        return $this->nullMethod($var);
    }
    if ($var==1){
        return $this->oneMethod($var);
    }
    if($var==2){
        return $this->twoMethod($var);
    }
    if($var==3){
        return $this->threeMethod($var);
    }
    if($var==4){
        return $this->fourMethod($var);
    }
}

Array Approach Method calling

public function checkData($var){
 $array_methods = [
    '1'=>'oneMethod',
    '2'=>'twoMethod',
    '3'=>'threeMethod',
    '4'=>'fourMethod',
    ];
    return $this->{$array_methods[$var]($var)};

    //to simplify, break it down
    $method=$array_methods[$var];
    return $this->{$method}($var);
}

Comments

[microerror]

PHP 8.x exposes match which turns your entire article into

return match($data) {
    1 => 'one',
    2 => 'two',
   default => 'default value'
};

There's no need for arrays or early returns, this is as concise as it gets.

[Timothy Soladoye]

Yes @microerror ,

The match expression can also be used to replace nested if else statement