C++ :: How To Allow User To Input Operator Into Calculator Function
Aug 24, 2014
How I can let the user input a certain operator into this calculator function?. I would like to use cin to input the operator if possible because it is one of the only input commands I know.
// Calculator.cpp : Defines the entry point for the console application.
// Calculates the value of two numbers based on the four main operations.
#include "stdafx.h"
#include <iostream>
int add(int x, int y);
int subtract(int x, int y);
int multiply(int x, int y);
int divide(int x, int y);
I am doing an assignment that is to calculate the federal tax based on the users input. I am not entirely sure what it is doing, but it is definitely not what I want it to do. I commented out the loops because they seemed to have caused a problem, but there is still problems that are making the program do something else. Here is my code:
#include<iostream> #include<string> using namespace std; double getData(); double taxAmount();
[Code] ....
Functions just seem like they are not my thing. It never gets to the second function to do the calculations and then return to main to display the results.
I tried changing the code to a switch(status) with a default: at the end that looped the "please try again" but for some reason, that was a fail, it created an endless loop.
I am working on a simple calculator in C++ .... All works fine with the calculator up until the requirement for the user to input "do you want to go again y/n" .... What i want to happen is the screen to clear down and reloop to the enter name part....but i can't get it to do that
Program Description: To write and develop a programme where a user can input a cost or price of something before VAT our program must then process the input number and must output the price with the original value plus VAT
#include <iostream>// I must use this to start my programming #include <string> // I have added this for the extension task so the user has to input their name #include <iomanip> // this is to manipulate the text #include <stdlib.h> using namespace std; // using the "using namespace std" shows that i will be using standard text throughout this programme
I tried to scanf the input by the user into the function but it does not read my input. Read on one of the thread, it said that to scanf a input into a double, need to use %1f instead to %d (which normally used. I tried changing it to %1f and it still did not work.
Code: #include <stdio.h> #include <math.h> /* function main begins program execution */ int main( void ) { double amount; /* amount on deposit */
Firstly, I'd like to say that I'm relatively new to functions and my course standards state that I'm now supposed to relay information from the user to the program via functions, this means that I'm no longer able to use 'printf/scanf' combos in the main function.
Is it possible to do it via functions? I've tried the following method for example, but to no avail.
Code: #include <stdio.h> int getlowR(); int main(void) { getlowR();
[Code] ....
I think the following works but then lowRange is native to the function, isn't it? How can I use it outside the function? For example, how would I go about actually printing the value acquired by the function in main?
I have am having a bit of trouble with a baisc calculator that I am writing for my intro to programming class at Uni. We are using the C programming language. The program is supposed to be able to add, subtract, multiply, and divide. It is also supposed to return certain messages if an error has occurred. This is how the program is supposed to perform:
bash-4.2$ ./calc enter expression: 4.25 * 3.3 result: 14.025
In my calculator, I am trying to make it so that you put enter 1 to add, 2 to subtract, 3 to multiply, and 4 to divide. I am facing the issue of making it so that you must enter a number, however instead of it being any number, it must be 1, 2, 3, or 4, and if it is not any of those numbers, you must re-enter the number. Here is a little snippet of my code:
Code:
printf("Please enter 1 to add, 2 to subtract, 3 to multiply, or 4 to multiply: "); while (scanf("%d", &input) != 1) { while (getchar() != ' '); printf("Invalid option. Please try again: ");
I'm writing an addition and subtraction calculator that takes input as: 5+6-3+2. You should be able to add or sub as many numbers as you want. I want the while loop to stop when the user hits enter. I put the getchar() function to catch the and break the loop but it is also swallowing the '-' sign, which I want to use to subtract and is instead adding the numbers with "sum+=number". How can I get around that?
Code:
#include <stdio.h> int main(int argc, char *argv[]){ int number, sum = 0;
i'm trying to write a calculator. the user will enter the terms and they will be stored in arrays. i will be storing those terms in string arrays and then later turn them to double to work with them. but the user should be able to enter terms like sin(252) and the program should be able to recognize it and calculate it.
How to get this thing to work. All i need to do is ask user to input a name and then it brings out the line from the .txt file containing the information.
For example in my case I'm doing a member search function I'm required to ask user to input the name of the customer and then print out all the details (which consumes 1 text line in the .txt file)
Here is the code, This is the write to text file method (100% working)
I have my Reverse Polish calculator compiling and everything but for the assignment I need to handle a few exceptions that I can't seem to get. First off I'm trying to make the program exit if the user enters only "0" but since the input i'm using is string, I cant figure out how to code
"If the first node is 0 and the next node = NULL, return true"
Here is my code: #include<iomanip> #include<iostream> #include<stdlib.h> #include<stdio.h> #include<string> #include<sstream> using namespace std;
I am studying about recursion by myself and i want to make a recursive function that prompts the user to input the base and exponent and generate the final answer .
#include<iostream> using namespace std; int recursive(int x, int y); int main() { /*int total=1; int y, x;
#include <iostream> using namespace std; class Date { private: int month, day, year; public: // class constructors can be overloaded Date(int m, int d, int y) {
[Code] ....
Actually ,I'm not sure whether my understanding of operator>> function is correct. Here is my understanding of operator>> function.....
operator>> function takes Date object as argument from main function and it reads data from the console using istream(This is all I know about istream) into the new Date object which is created by operator>> function..
This is all I know about operator>> function...I really don't know why it has to return istream reference(I know the return type is istream, but other than that ? I want to know why operator>> function creates new Date object ? It already has a reference to Date object ....why not simply set the values of the already existing Date object instead of creating one..?
error C2660: 'Add' : function does not take 0 arguments error C2660: 'Subtract' : function does not take 0 arguments error C2660: 'Multiply' : function does not take 0 arguments error C2660: 'Divide' : function does not take 0 arguments
I made a basic console calculator in C++ using the Code::Blocks IDE and using the GNU GCC compiler. The problem in my code is my void function called 'operate' is getting ignored by not showing up in the console. After the first if statement I added a user input by saying Y for yes or N for no. Another if statement inside the first one shows if you type either 'Y' or 'y' it will execute the 'operate' function which will restart the calculator by having the same selection menu as in the int main function. When I call the function it does not show up in the console but just ends the program.
Here is my code:
#include <iostream> #include <cstdlib> #include <string> using namespace std; int input,input2, numAdd, numAdd2, numSub, numSub2, numMult, numMult2, numDiv, numDiv2; void operate() { cout << "Select a operator." << endl;
I am making program that allows the user to determine how big the array size will be and then asks the user to make up numbers to fill the array. Every time run the program on Dev C++ it says "program has stopped working"
Heres My Code:
//Assignment 19 Program 2 #include <iostream> using namespace std; int main()
i am doing some practice problems and i can't seem to figure out how to do this. basically we have a students number of test scores, then the name followed by the scores they have in a text file. Then we have to make a class with a constructor, copy constructor, destructor, and overload the = operator and the input and output operator. Are we suppose to call the text file in the input overload operator?
Here is what i have so far.
This is my header file.
#ifndef STUDENTTESTSCORES_H #define STUDENTTESTSCORES_H #include <string> #include <iostream> using namespace std; class StudentTestScores{ private: string studentName;
[Code]...
i am 100% sure the overloading the input is wrong
here is the implementation of the constructor copy constructor and desctructor
#include <iostream> #include "StudentTestScores.h" using namespace std; StudentTestScores::StudentTestScores(string name = "", int numScores = 0) { studentName = name; numTestScores = numScores; if (numScores <= 0) testScores = NULL; else
[Code]...
and here is the notepad file
3 Justin Bieber491.469.184.681.081.5 Miley Cyrus380.080.090.083.3 Kim K490.575.661.481.677.2
The program is suppose to use all the information and read from the notepad and output the exact things as the notepad file
I wrote a simple Complex Class and overload input/output and +/- Operators in it!But there is something that doesn't work correctly!I can print an object of that class but I can't print sum of two object or something like that!
The premise of this assignment is to create a menu driven, array of functions calculator. This is the code I have thus far (I haven't finished all of my comments yet, I've been to focused on clearing errors).
/*prototypes*/ void sum (int a, int b); void dif (int a, int b); void pro (int a, int b); void quo (int a, int b); void printMenu();
[Code] .....
I am using Visual Studio as a compiler, and I have the following errors:
error C2144: syntax error : 'int' should be preceded by ')' error C2660: 'sum' : function does not take 0 arguments error C2059: syntax error : ')' error C2144: syntax error : 'int' should be preceded by ')'
[Code] .....
I can only assume that I am making simple mistakes.
I cannot get my function overloading the input operator for rational type objects to work.
lab9.cpp: In function ‘std::istream& operator>>(std::istream&, const rational&)’: lab9.cpp:186:20: error: invalid initialization of reference of type ‘std::istream& {aka std::basic_istream<char>&}’ from expression of type ‘rational’ return (inputFrac);
lab9.h
#include <iostream> using namespace std; class rational { public: rational(); rational(int a, int b);
why can't << operator be overloaded as a member function is it because that is the way c++ is written and you just can't or is there another reason because I'm confused.
