ltrim函数不能按预期工作？ PHP

Question

I am using ltrim function. I run this code :

echo ltrim("looooooooooooooooooooooooongWord","long");

i expect to get this word : looooooooooooooooooooooooongWord but it prints Word.

what's the problem ?

Edit: I thought it remove the word long, but it appears it remove the l,o,n,g characters !

Answer 1

ltrim — Strip whitespace (or other characters) from the beginning of a string

It does exactly as it says, strips chars l, o, n, g.