IF statements

Hey all.

I'm new to programming, and im currently at lesson 2 about If statements. I used the example given in the thread, and tried to create one very similar, but it's not made correctly.

Here is the code, hope someone can tell me whats wrong:

Code:

---

#include iostream

using namespace std;

int main()

{
    int age;

    cout<<"How old are you? ";
    cin>> age;
    cin.ignore();
    if (age < 20); {
            cout<<"You are young.\n";
    }
    else if (age = 20) {
        cout<<"You are pretty.\n";
    }
    else (age > 20) {
        cout<<"You are old!\n";
    }
}

---

no semicolon after a 'IF' statement allowed:

Code:

---

if (age < 20);

---

'else' is not a conditional statement.. it is a block of code that is executed if all other 'if's or 'else if's' have been attempted:

Code:

---

else (age > 20)

//should just be

else
{ //stuff here }

---

> else if (age = 20)
Also, use == for comparison,
= is assignment.

Hmm.. It's still not working, the program says there is something wrong with this line:

Code:

---

cout<<"Please input your age: ";

---

I tried to fix by adding \n, but it's still not working.

Here's the hole code again:

Code:

---

#include iostream

using namespace std;

int main()

{
    int age;

    cout<<"Please input your age: ";
    cin>> age;
    cin.ignore();
    else (age < 20) {
        cout<<"You are young.\n";
    }
    else if (age == 20) {
        cout<<"You are pretty.\n";
    }
    else (age > 20) {
        cout<<"You are old!\n";
    }
}

---

Your first else should be an if.

Still doesnt work, look at my post again. The program (dev-C++) makes an error at this line, and i really can't see whats wrong. I tried adding \n in the end, but that doesnt help.

Code:

---

cout<<"Please input your age: ";

---

> The program (dev-C++) makes an error at this line
Well posting the actual error message would help.

Also, a single line in isolation doesn't say much. It's also pretty likely that the actual error is on a preceding line and this is just the first line that the compiler notices that there is something wrong.

For such a short program, reposting the whole thing again is the best course.

Could be that you use #include iostream instead of #include <iostream>, but the compiler should complain about that.

Quote:

---

#include iostream

---

Can't imagine 3 people missed this one ;)
See anything that's missing?

The error line is:
'cout' undeclared (first use this function).

This is the hole code:

Code:

---

#include iostream

using namespace std;

int main()

{
    int age;

    cout<<"Please input your age: ";
    cin>> age;
    cin.ignore();
    if (age < 20) {
        cout<<"You are young.\n";
    }
    else (age == 20) {
        cout<<"You are pretty.\n";
    }
    else (age > 20) {
        cout<<"You are old!\n";
    }
}

---

I had to use:

<iostream>
instead of
iostream

thx for all the replies.

> Here is the code, hope someone can tell me whats wrong:
Your compiler will tell you what's wrong.

Code:

---

$ g++ foo.cpp
foo.cpp:1:10: error: #include expects "FILENAME" or <FILENAME>
foo.cpp: In function ‘int main()’:
foo.cpp:10: error: ‘cout’ was not declared in this scope
foo.cpp:11: error: ‘cin’ was not declared in this scope
foo.cpp:16: error: expected primary-expression before ‘else’
foo.cpp:16: error: expected `;' before ‘else’
foo.cpp:19: error: expected primary-expression before ‘else’
foo.cpp:19: error: expected `;' before ‘else’

---

Start at the top, and work your way through the error messages. Just fixing the #include gets rid of 3 errors.