C_cha08.pptVIP

Outline Key Points 8.1 Introduction Introduce some standard library functions Easy string and character processing Programs can process characters, strings, lines of text, and blocks of memory These techniques used to make Word processors Page layout software Typesetting programs 8.2 Fundamentals of Strings and Characters Characters Building blocks of programs Every program is a sequence of meaningfully grouped characters Character constant An int value represented as a character in single quotes z represents the integer value of z Strings Series of characters treated as a single unit Can include letters, digits and special characters (*, /, $) String literal (string constant) - written in double quotes Hello Strings are arrays of characters String a pointer to first character Value of string is the address of first character 8.2 Fundamentals of Strings and Characters String declarations Declare as a character array or a variable of type char * char color[] = blue; char *colorPtr = blue; Remember that strings represented as character arrays end with \0 color has 5 elements Inputting strings Use scanf scanf(%s, word); Copies input into word[] Do not need (because a string is a pointer) Remember to leave room in the array for \0 8.2 Fundamentals of Strings and Characters An array of characters Used to store text Another way to initialize: char str[] = Text; Instead of char str[] = {‘T’,’e’,’x’,’t’}; 8.2 Fundamentals of Strings and Characters Where does it end? 8.2 Fundamentals of Strings and Characters Strings terminate with the \0 character (ASCII code 0) This is a convention used to know where the string ends It means that in order to hold a string of N characters we need an array of length N + 1 So: char str[] = Text; Is equal to: char str[] = {T, ‘e, ‘x, ‘t, \0}; 8.2 Fundamentals of Strings and Characters What does it print? 8.2 Fundamentals of Strings and Characters Reading strings There are several ways of accepting strings as input from the