Functions

[gottalovecoding3]

Hello,everyone! I have to write a program that check if a string contains only allowed symbols like
+, -, *, / and (), [], {} using a function and I need your help.

[Thomas1965]

You need to loop through all the chars in the string.
If the char is not allowed return false.
After the loop return true.
A starting point:

#include <iostream>
#include <string>

using namespace std;

bool valid_string(const string& input)
{
  // place your code here
}

int main()
{
  string input;
  cout << "Enter string to test: ";
  getline(cin, input);
  bool valid = valid_string(input);
  if (valid)
    cout << "valid";
  else
    cout << "Not valid";
}

[SamuelAdams]

think about the process you would do this on pen and paper. Then code it.

hint: this will help you a lot
http://www.cplusplus.com/reference/string/string/size/