if statement

[formal summit]

#include <iostream>

bool isPrime(int x) {
  if (x == 2)  // if user entered 2, the digit is prime
    return true;
  else if (x == 3)  // if user entered 3, the digit is prime
    return true;
  else if (x == 5)  // if user entered 5, the digit is prime
    return true;
  else if (x == 7)  // if user entered 7, the digit is prime
    return true;

  return false;  // if the user did not enter 2, 3, 5, 7, the digit must not be
                 // prime
}

int main() {
  std::cout << "Enter a number 0 through 9: ";
  int x{};
  std::cin >> x;

  if (isPrime(x))
    std::cout << "The digit is prime\n";
  else
    std::cout << "The digit is not prime\n";

  return 0;
}

[glad pebble]

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[formal summit]

I dont understand how

else in main and
.return false in the top bool function

Communicate

[west urchin]

isPrime(number) results in false
If the condition in an if statement is false, it executes the else branch

[formal summit]

#include <iostream>

bool isPrime(int x) {
  if (x == 2)  // if user entered 2, the digit is prime
    return true;
  else if (x == 3)  // if user entered 3, the digit is prime
    return true;
  else if (x == 5)  // if user entered 5, the digit is prime
    return true;
  else if (x == 7)  // if user entered 7, the digit is prime
    return true;

    else
     return false;
}

int main() {
  std::cout << "Enter a number 0 through 9: ";
  int x{};
  std::cin >> x;

  if (isPrime(x))
    std::cout << "The digit is prime\n";
  else
    std::cout << "The digit is not prime\n";

  return 0;
}

[formal summit]

;compile

[urban saffron]

Program Output

Enter a number 0 through 9: The digit is not prime

Compiler Output

<source>: In function 'bool isPrime(int)':
<source>:13:1: warning: control reaches end of non-void function [-Wreturn-type]
   13 | }
      | ^

Oppenheimer#2437 | 71ms | c++ | x86-64 gcc 12.2 | godbolt.org

[formal summit]

;compile

[urban saffron]

Program Output

Enter a number 0 through 9: The digit is not prime

Oppenheimer#2437 | 53ms | c++ | x86-64 gcc 12.2 | godbolt.org

[formal summit]

@west urchin i removed return false.

[west urchin]

Then if you don't input 2 3 5 or 7, then the result of isPrime could be anything

[formal summit]

;compile

[urban saffron]

Program Output

Enter a number 0 through 9: The digit is not prime

Oppenheimer#2437 | 100ms | c++ | x86-64 gcc 12.2 | godbolt.org

[formal summit]

@west urchin check it works i put an else statement and wrote return false to make it make sense

[shadow remnant]

;compile | 3

[urban saffron]

Program Output

Enter a number 0 through 9: The digit is prime

Paweł Syska#4065 | 71ms | c++ | x86-64 gcc 12.2 | godbolt.org

[shadow remnant]

[formal summit]

Whats up?

[shadow remnant]

I forgot how to pass input using the compiler bot

[west urchin]

Looks good

[formal summit]

We on the same page for once

[formal summit]

@west urchin can you please address my addition for the else statement in the book function

[jolly cargo]

The else that you added to isPrime? Its unnecessary

[formal summit]

Why??

[jolly cargo]

Because it's the same as not having it. The only way to end up at the end is for all the if and else ifs to be false

[formal summit]

Yeah exactly I love those words let me say who is gonna know whats at the end

Thts exactly what I'm asking

[formal summit]

@jolly cargo you there?

[jolly cargo]

Yes

[formal summit]

Yeah bout this

[jolly cargo]

What about it?

[formal summit]

Yes I agree but who calls the end who knows whats at the end?@jolly cargo

[glad pebble]

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[formal summit]

!solved