Need help with my beginner calculator code

[Ingus117]

Can someone please tell me why this shows some weird results?
it compiles, but it doesn't do what it is supposed to, and I am really confused as to why. It is a really basic calculator code I have been working on.

#include <iostream>
#include <cmath>
#include <string>
using namespace std;

int main()
{
	double x,y,l,result;
	char operators,funkcija,funkcCal,aritmCal,w;
	int Pi = 3.14159265359;
      cout << "Velaties izmantot aritmetikas vai funkciju kalkulatoru?" << endl;
      cin >> w;
  if (w == 'funkciju kalkulators' || 'funkciju')
  goto funkcCal; 
  else 
  goto aritmCal;

  aritmCal:
        cout << "Ievadiet izteiksmi:" << endl;
        cin >> x;
        cin >> operators;
        cin >> y;
  if (operators == '+')  result = x+y;
  if (operators == '-')  result = x-y;
  if (operators == '*')  result = x*y;
  if (operators == '/')  result = x/y;
        cout << endl;
        cout << "Rezultats:" << " " << result << endl;
  
  funkcCal:
  	cout << "ievadiet funkciju:" << endl;
  	cin >> l;
  if (funkcija == 'cos')  result = (x*Pi/180);
  if (funkcija == 'sin')  result = (x*Pi/180);
  if (funkcija == 'tan')  result = (x*Pi/180);
  if (funkcija == 'exp')  result = exp(x);
  if (funkcija == 'log')  result = log(x); 
  if (funkcija == 'sqrt') result = sqrt(x);
        cout << endl;
        cout << " " << result;
  
  return 0;
}

Sorry the text is in Latvian, I will put the translations below.

Velaties izmantot aritmetikas vai funkciju kalkulatoru? == Do you wish to use arithmetical or function calculator?

funkciju kalkulators == Function calculator

Ievadiet izteiksmi: == Input the problem:

ievadiet funkciju: == Input the function:

[AbstractionAnon]

Line 13: C++ does not support an implicit left hand side.
Line 13: w is defined as a single char. You can't compare against multi-character literals.
Line 13: Single quotes define single character literals. If you want to compare strings, use double quotes. w should also be a string. Note that if you're going to use cin with multiple words, you should use getline(). cin stops at the first space.
Line 14,16: Avoid the use of goto This is a bad practice to get into.
Line 27: arithmetic calculator falls through to function calculator.
Line 32-37: Improper use of single quotes again.

[Ingus117]

Thank you very much!

[andywestken]

it compiles, ...

Did the compiler not warn you about these problems?

If not, you need to up the warning level you're using.

GCC with -Wall -Wextra -pedantic

.../main.cpp:13:12: warning: character constant too long for its type [enabled by default]
if (w == 'funkciju kalkulators' || 'funkciju')
         ^
.../main.cpp:13:38: warning: character constant too long for its type [enabled by default]
if (w == 'funkciju kalkulators' || 'funkciju')
                                   ^
.../main.cpp:32:19: warning: multi-character character constant [-Wmultichar]
if (funkcija == 'cos')  result = (x*Pi/180);
                ^
W:/Source/Explore/cplusplus_gcc/temp_test/main.cpp:33:19: warning: multi-character character constant [-Wmultichar]
if (funkcija == 'sin')  result = (x*Pi/180);
                ^
etc

I guess you're probably using GCC as MSVC won't even build your code, let alone run it. (Or Clang??)

1>------ Build started: Project: temp_test, Configuration: Debug Win32 ------
1>  main.cpp
1>main.cpp(10): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>main.cpp(13): error C2015: too many characters in constant
1>main.cpp(13): error C2015: too many characters in constant
1>main.cpp(13): warning C4127: conditional expression is constant
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Other problems...

Line 10 - pi needs to be a double rather than int
Line 33-35 - looks like something's missing??
And if you stick with goto, you're missing one? (But should switch to a different solution.)

Andy

[Ingus117]

what should I use instead of goto?

[Ingus117]

This is how far I got on that code, but it still doesnt work like it should, not by a long shot!

#include <iostream>
#include <cmath>
#include <string>
using namespace std;


int main()
{
	string o,funkcija;
	double x,y,l,result;
	double Pi = 3.14159265359;
	char operators;
  cout << "Velaties izmantot aritmetikas vai funkciju kalkulatoru?" << endl;
  getline(cin,o);
    if (o == "funkciju kalkulators" || "funkciju" || "oo")
    {
  	cout << "ievadiet funkciju:" << endl;
  	cin >> l;
    if (funkcija == "cos")  result = (x*Pi/180);
    if (funkcija == "sin")  result = (x*Pi/180);
    if (funkcija == "tan")  result = (x*Pi/180);
    if (funkcija == "exp")  result = exp(x);
    if (funkcija == "log")  result = log(x); 
    if (funkcija == "sqrt") result = sqrt(x);
    cout << endl;
    cout << " " << result;
	}
   else if (o == "Izteiksmju kalkulators" || "izteiksmi" || "aa")
   {
  
    cout << "Ievadiet izteiksmi:" << endl;
  cin >> x;
  cin >> operators;
  cin >> y;
    if (operators == '+')  result = x+y;
    if (operators == '-')  result = x-y;
    if (operators == '*')  result = x*y;
    if (operators == '/')  result = x/y;
     cout << "Rezultats:" << " " << result << endl;
   }
  else
  {
  	cout << "error" << endl;
  }

    return 0;
}

I am really confused why it only goes to function calculator no matter what. And it even doesnt execute it properly, just prints out some nonsense numbers

[AbstractionAnon]

Line 15, line 28: You did not correct the implied left hand side.

if (o == "funkciju kalkulators" || "funkciju" || "oo")

The two underlined expressions always evaluate to true (they are pointers), therefore the if statement always evaluates as true.

It should be:

if (o == "funkciju kalkulators" || o == "funkciju" || o == "oo")

[Ingus117]

omg I didn't even consider that. Thank you very much!

[Feymanismyhero]

Instead of goto, use separate functions and just call the functions.