tailieunhanh - C for Dummies 2nd edition phần 3

ông printf () và scanf () chức năng không phải là cách duy nhất bạn có thể hiển thị thông tin hoặc đọc văn bản từ bàn phím - cũ I / O. Không, C lan đánh giá là đầy đủ các thủ đoạn I / O, và khi bạn tìm ra cách hạn chế và què printf () và scanf (), | 64 Part I Introduction to C Programming Chapter 6 C More I O with gets and puts Jn This Chapter Reading strings of text with gets Avoiding some gets problems Using puts to display text Displaying variables with puts Knowing whether to use puts or printf he printf and scanf functions aren t the only way you can display information or read text from the keyboard that old I O. No the C language is full of I O tricks and when you find out how limited and lame printf and scanf are you will probably create your own functions that read the keyboard and display information just the way you like. Until then you re stuck with what C offers. This chapter introduces the simple gets and puts functions. gets reads a string of text from the keyboard and puts displays a string of text on the screen. The More J Want the More J gets Compared to scanf the gets function is nice and simple. Both do the same thing They read characters from the keyboard and save them in a variable. gets reads in only text however. scanf can read in numeric values and strings and in a number of combinations. That makes it valuable but for reading in text clunky. 66 Part I Introduction to C Programming Like scanf reading in text gets requires a char variable to store what s entered. It reads everything typed at the keyboard until the Enter key is pressed. Here s the format gets var gets like all functions is followed by a set of parentheses. Because gets is a complete statement it always ends in a semicolon. Inside the parentheses is var the name of the string variable text in which it is stored. Another completely rude program example The following is the program. This program is almost identical to the program introduced in Chapter 4 except that gets is used rather than scanf . include int main char j erk 20 printf Name some jerk you know gets jerk printf Yeah I think s is a jerk too. n jerk return 0 Enter this source code into your .