How to use single and double quotation marks in strings? In all programming languages, you must open and close your string with quotation marks, but you don't have to, if your interpreter doesn't ...

The main problem you're having is that strlen calculates the length of the string data already in the string you give it. out is not initialized when you pass it to strlen so the result is undefined.

If you program in C, strings are just in your imagination. What you really have is a character pointer, and we all agree that a string is every character from that point up until one of the characters ...