C programming language (2nd Edition) -- Reading Notes -- 1.5

        Look at a group of programs dealing with character data . Will find , Many programs are extensions of the program prototype .

        Input from the standard library / The output model is simple . No matter where the text is entered , Where to export , Its input / Output is processed in the way of character stream . A text stream is a sequence of characters composed of multiple lines of characters , Each line of characters is composed of 0 Or more than one character , The end of the line is a newline . The standard library makes every input / The output stream can follow this model . Use standard library C Language programmers don't have to worry about how these lines are represented outside the program .

        Provided by standard library once read / Write One Character functions , The simplest is getchar and putchar function . Every time you call ,getchar Function reads the next input character from the text stream , And return it as the result value . namely , perform

c = getchar()

after , Variable c Will contain the next character in the input stream . This kind of character is usually input by keyboard . The method of inputting characters from files will be discussed in Chapter 7 .

        Every time you call putchar Function will print a character . for example

putchar()

Will set integer variables c The contents of are printed in character form , It is usually displayed on the screen .putchar And printf Functions can be called alternately , The output order is consistent with the call order .