《C语言课程设计案例精编》课件 2-2.pptVIP

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 变量先说明，然后赋值，也可以在定义的时候初始化。 * * * * * * * * * 在一个逻辑表达式中，其优先级是：！最高， 次之，||最低；逻辑运算优先级低于所有关系运算，而！优先级高于所有算术运算。关系运算符的优先级低于算术运算。 * 位否定，位左移，位右移，位与，位或，位异或（相同为0，不同为1） * * * * * * * * formatted Output Form: printf (“format string”, arg1,arg2,…) format string specifies the output form of variables. arg1,arg2….are arguments. According to the specification in format string, function printf() translates internal values to output through the arguments. The format string usually contains conversion specifications and ordinary characters. The former is used to control conversion of output, and the later is copied to the output stream. Each conversion specification begins with a % and ends with a conversion character. Between the % and the conversion character there may be, in order: A number sign (-), which specifies left adjustment of the converted argument. A number (m) that specifies the minimum field width. A period (,), which separates the field width from the precision, called separator. A number (.n), the precision, that specifies the maximum number of character string, or the number of digits after the decimal point of a floating-point value, or the minimum number of digits for an integer. formatted Output (cont.) formatted Output (cont.) Characters Argument types; Printed as d, i Decimal integer o Unsigned octal integer X, x Unsigned hexadecimal integer u Unsigned decimal integer c int; single character s char; f double E, e double G, g double p Void pointer #include stdio.h main( ) { printf (This is a C program.\n); } #include stdio.h main( ) { int a=1, b=2, c=100, d; printf(a=%d, b=%3d, d=%3d%%\n,a, b, a*c/b); printf(%d, %o, %x\n, -a, -a, -a); } formatted Output (cont.) Output: a=1, b= 2, d= 50% -1, 177777, ffff Output: This is a C program. formatted Output (cont.) #include stdio.h main ( ) { char c=a; char ch[ ]=Good-bye.; printf( %c, %3c, %3d\n,