C Programming for Engineers: Lecture 16 - C Strings, Study notes of Engineering

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CSE294A

Introduction to C Programming for Engineers

Lecture

Jeffrey Miller, Ph.D.

C Strings

C strings are different than C++ strings, which youwill learn next semester

C strings are nothing more than an array ofcharacters, though there are special functions thatcan be used on them that can not be used on othertypes of arrays - Since C strings are arrays, we can also usepointers with them

Populating C Strings

To give values to C strings, you can set individual characters char my_str[10]; my_str[0] = ‘h’; my_str[1] = ‘i’; my_str[2] = ‘\0’; - You can also read the data from the user char my_str[10]; scanf(“%s”, my_str); // no &…why? - NOTE: Since C strings are terminated by the null character \0, youactually have one character less than the value in the brackets allocatedto your string

C String Functions

int strcmp (const char, const char);

Returns negative value if first string is less thansecond one

Returns 0 if the strings are the same - Returns positive value if first string is greaterthan second one - NOTE: For the C String functions, it isnecessary to include the cstring library #include

C String Functions

char strcpy(char, const char*);

Copies the contents of the second string into thefirst string

Returns a pointer to the new string - When strcmp on the two strings is called, 0 isreturned

C String Functions

size_t strlen (const char*);

Returns the length of the string, minus the \

size_t is a non-negative int, so it can be treatedas an int

Homework

Homework #7 will be posted soon!