PHP in_array() Function

Syntax of in_array in PHP

The in_array() function in PHP is used to check if a given value exists within an array. It returns a boolean value (true if the value is found, false if not). Here's the syntax of the in_array() function:

• mixed $needle:

  The value you want to search for within the array. It can be of any data type, such as string, integer, float, or even an array.

• array $haystack:

  The array in which you want to perform the search.

• bool $strict (optional):

  If set to true, the function performs a strict type comparison (both value and type must match). If set to false (default), only the value is compared.

Parameters of in_array in PHP

The in_array() function in PHP is used to check if a given value exists within an array. It takes three parameters, with one of them being optional. Here are the parameters of the in_array() function in detail:

• mixed $needle:

  This is the value you want to search for within the array. It can be of any data type (e.g., string, integer, float, array, object). The function will look for this value within the array.

• array $haystack:

  This parameter specifies the array in which you want to perform the search. The function will examine this array to find if the given value exists.

• bool $strict (optional):

  This parameter determines whether the comparison should be strict or not. If set to true, both the value and the type of the elements will be considered in the comparison. If set to false (which is the default), only the values will be compared. This parameter is optional, and if omitted, the default value of false will be used.

Return Value of in_array in PHP

The in_array() function in PHP returns a boolean value that indicates whether a given value exists within an array. It returns true if the value is found in the array and false if the value is not found. The function performs a linear search through the array to determine the presence of the value. Here are the details of the return value:

• If the value is found within the array, in_array() returns true.
• If the value is not found within the array, in_array() returns false.

Examples of in_array in PHP

Search for the value in an array and output some text

Output

• We start by defining an array called $fruits containing a list of fruits.
• We specify the fruit we want to search for by assigning the value 'banana' to the variable $searchedFruit.
• We use an if statement to check whether the searched fruit exists in the array. We do this by using the in_array() function, which returns true if the value is found and false if it's not found.
• If the fruit is found (if condition is true), we use echo to output a message indicating that the fruit is found in the array.
• If the fruit is not found (if condition is false), we use echo to output a message indicating that the fruit is not found in the array.

Using PHP in_array() function with the searched value is an array

Output

• We start by defining an array called $fruits containing a list of fruits.
• We define an array called $searchedFruits, which contains the fruits we want to search for within the $fruits array.
• We use the in_array() function to check if the entire $searchedFruits array is found as a subarray within the $fruits array. The function returns true if all elements of the $searchedFruits array are found within the $fruits array, and false if they are not found.
• If all searched fruits are found (if condition is true), we use echo to output a message indicating that all searched fruits are found in the array.
• If not all searched fruits are found (if condition is false), we use echo to output a message indicating that not all searched fruits are found in the array.

Using all parameters

Output

• mixed $needle:

  We specify the value 3 as the needle to search for within the array.

• array $haystack:

  The array $data is the haystack in which we want to perform the search.

• bool $strict = true:

  We set the $strict parameter to true to perform a strict comparison. This means that not only the values but also the types must match.

• We use an if statement to check if the value 3 exists in the array $data using the in_array() function with strict comparison.

• If the value 3 is not found ($needle is 3, but 3 is not equal to '3' with strict comparison), the else block is executed, and a message is outputted indicating that the value is not found in the array.