Convert multiple instances of a character to only one (aa = a) using preg_replace?

Question

I have a string, I want to convert several expressions - only to one - .

I tried preg_replace('/--+/g', '-', $string) , but that just returns nothing ..

Answer 1

You should not use g in the pattern, and you can simplify your regex:

 preg_replace('/-+/', '-', $string); 

Backslash screens are not required.

On http://ideone.com/IOlpv :

 <? $string = "asdfsdfd----sdfsdfs-sdf-sdf"; echo preg_replace('/-+/', '-', $string); ?> 

Conclusion:

 asdfsdfd-sdfsdfs-sdf-sdf 

Answer 2

 preg_replace('/([\-]+)/', '-', $string) 

Answer 3

Your code displays the following error:

Warning: preg_replace (): Unknown modifier 'g'

No modifier g . Try:

 preg_replace('/--+/', '-', $string)