PHP Function that call itself does not return anything

Question

This is not returning anything:

<?php

function cc($i=0) {
    if ($i >= 2) {
       return $i;
    }
    cc($i+1);
}
echo cc(0);

But with echo it's working perfectly:

<?php

function cc($i=0) 
{
    echo $i;
    if($i>=2) {
       return $i;
    }
    cc($i+1);
}
echo cc(0);

Looks preety wierd to my eyes but I'm quite sure there is a logical explanation behind it :)

Answer 1

It doesn't return anything because you missed a return in the recursive call. Use this:

function cc($i=0) {
  if($i>=2){
    return $i;
  }
  return cc($i+1);
}

Using ternary operator:

function cc($i=0) {
  return $i>=2 ? $i : cc($i+1);
}