array_reduce() Method: As the name suggests, an array_reduce() function reduces the array to a single value by performing the given operation. The array_reduce() applies the callback function to the elements of the array and gives output as a single value.
array_walk() Method: It applies a user-defined function to every member of an array. The array’s keys and values are parameters in the function. The array_walk() function is not affected by the internal array pointer of the array.