A simple calculator for C language lesson 1, a calculator for Lesson 1

A simple calculator for C language lesson 1, a calculator for Lesson 1

I have been learning C language since I made a simple calculator in C language for so long. /* C language lesson 1 simple calculator */# include <stdio. h> # include <stdlib. h> # include <conio. h> Void displayMenu (); Void add (); Void sub (); Void multiply (); Void divide (); Void yushu (); Void jiecheng (); Void leijia (); Void jiechengleijia (); Int main (int n) {Do {System ("color 2e "); System ("cls "); DisplayMenu (); System ("pause ");} While (n );} Int n; Void displayMenu () {Printf ("*** welcome to use simple calculator *** \ n "); Printf ("the author is xiaobo \ n "); Printf ("No.1 add \ n "); Printf ("No. 2 sub \ n "); Printf ("No. 3 multiply \ n "); Printf ("No. 4 divide \ n "); Printf ("No. 5 yushu \ n "); Printf ("No. 6 jiecheng \ n "); Printf ("No. 7 liejia \ n "); Printf ("No. 8 jiechengleijia \ n "); Printf ("No.0 exit \ n "); Scanf ("% d", & n ); Switch (n) {Case 1: add (); break; Case 2: sub (); break; Case 3: multiply (); break; Case 4: divide (); break; Case 5: yushu (); break; Case 6: jiecheng (); break; Case 7: leijia (); break; Case 8: jiechengleijia (); break; Case 0: exit (0); return ;} } Void add () {Double num1, num2; Double sum; Printf ("Please Input 2 numbers to add \ n "); Scanf ("% lg", & num1, & num2 ); Sum = num1 + num2; Printf ("sum is % lg \ n", sum );} Void sub () {Double num1, num2; Double sum; Printf ("Please Input 2 numbers to sub \ n "); Scanf ("% lg", & num1, & num2 ); Sum = num1-num2; Printf ("the result is % lg \ n", sum );} Void multiply () {Double num1, num2; Double sum; Printf ("Please Input 2 numbers to multiply \ n "); Scanf ("% lg", & num1, & num2 ); Sum = num1 * num2; Printf ("the result is % lg \ n", sum );} Void divide () {Double num1, num2; Double sum; Printf ("Please Input 2 numbers to divide \ n "); Scanf ("% lg", & num1, & num2 ); Sum = num1/num2; Printf ("the result is % lg \ n", sum );} // Http://www.cnblogs.com/xiaobo-Linux/ QQ463431476 Void yushu () {Int num1, num2; Int sum; Printf ("please Input 2 numbers for yushu \ n "); Scanf ("% ld", & num1, & num2 ); Sum = num1 % num2; Printf ("yushu is % ld \ n", sum ); } Void jiecheng () {Double I, j = 1; Double sum = 1; Printf ("Please Input a integer number for jiecheng \ n "); Scanf ("% lg", & I ); For (; j <I; j ++) {Sum * = j ;} Sum * = I; Printf ("the result is % lg \ n", sum );} Void leijia () {Double n; Double sum = 0; Printf ("please input any number more than 0, with less than 0 number to end \ n "); For (n = 0; n> = 0 ;) {Sum + = n; Scanf ("% lg", & n );} Printf ("the result is % lg \ n", sum );} Void jiechengleijia () {Int I, a [5]; Long j, k = 1, sum = 0; Printf ("please input any 5 integer numbers \ n "); For (I = 0; I <5; I ++) {Scanf ("% d", & a [I]); For (j = a [I]; j> = 1; j --) {K = k * j ;} Sum + = k; K = 1 ;} Printf ("\ nthe sum is % ld \ n", sum );} /* 2014/12. 25 do */