查找键是否在多维数组中

Question

i am creating a multidimentional array and i wish to know why the following code is not working and why the other with same value when im fetching the same array is actually working.

$fruits = array(
  "sale"=> array("banana", "apple", "orange"),
  "regular"=> array("grapes", "pear", "ananas")
);

then in the first case it return false

1st case :

$find_price = 'sale';
if(in_array($find_price, $fruits)){
   return true;
}
else {
   return false;
}

and in second example i got a result of true

$find_price = 'sale';
if(isset($fruit[$find_price])){
   return true;
}
else {
   return false;
}

Answer 1

in_array() used to determine the value is in array or not. If you want to find if the key exist so array_key_exists is your friend

Look at the below snippet.

$find_price = 'sale';
if(array_key_exists($find_price, $fruits)){
   return true;
}
else {
   return false;
}

Answer 2

In your first code

$find_price = 'sale';
if(in_array($find_price, $fruits)){
   return true;
}
else {
    return false;
}

You use in_array() . This in_array() function the elements into the array, That element exist in array or not. And you are finding a value which is key in the array. Instead of in_array() you can use array_key_exists() .

Your second code

$find_price = 'sale';
if(isset($fruit[$find_price])){
   return true;
}
else {
   return false;
}

You are using isset() this function tell that the element you find, is exist in code or not. Like you are finding isset($fruit[$find_price]) means isset($fruit['sale']) that is exist....

Thats why this condition is true..

Answer 3

You have to use loop for this type of conditions. try this.

 foreach($fruits as $key => $value)
    {

      if($fruits[$key]['sale']) 
      {
          return true;
      }
    else 
    {
    return false;
    }

    }