Language in C 面接の質問と回答

Question: Why doesn't the following statement work?

char str[ ] = "Hello" ;
strcat ( str, '!' ) ;

Answer: The string function strcat( ) concatenates strings and not a character. The basic difference between a string and a character is that a string is a collection of characters, represented by an array of characters whereas a character is a single character. To make the above statement work writes the statement as shown below:
strcat ( str, "!" ) ;