Checking if array is multidimensional or not?

Question

1. What is the most efficient way to check if an array is a flat array of primitive values or if it is a multidimensional array?

Answer 1

All the above methods are too complex for quick rolling out. If an array is flat, testing the first element should return a primitive e.g int, string e.t.c. If it is multidimensional, it should return an array. By extension, you can use this one liner fast and neat.

echo is_array(array_shift($myArray));

if this returns true, the array is multidimensional. Else it is flat. Just to note, it is very rare for arrays to have different dimensions e.g. if you are generating data from a model, it will always have the same type of multidimensional or flat structure that can be traversed by loops. If it isn't, then you have custom built it by hand, which means you know where everything will be and it just works without needing to write a looping algorithm