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"if" Statements

An "if" statement is used to check if a condition is met. The program will execute branching logic based on the state of the condition tested.

Syntax


The syntax for an "if" statement looks like this:
if (condition)
{
    //the code that gets executed
}

Notice this looks a little different from Lua. The condition we are checking has to have (parenthesis) around it, and we use those funny-looking {curly brackets} around the code that gets executed when the condition is true.

Here's a simple example:

#include "Leadwerks.h";
int main(int argc, const char *argv[])
{
    if (2>1)
    {
        Print("Two is greater than one!");
    }
}

The above code tests to see if two is greater than one (it is!) and then goes on to execute the code inside the statement. The statement is terminated with the "end" keyword. So we know the above code would print out the word "true" when run.

Just like in Lua, you can compress "if" statements down to a single line to make them take up less vertical space. This code does the exact same thing as the previous example.

if (2>1) Print("Two is greater than one!");

Else


We can use the else keyword to make two branches of code that can be executed. One will be executed if the condition is met, and if it isn't then the other branch of code will be executed. Here's a simple example:
#include "Leadwerks.h";
int main(int argc, const char *argv[])
{
    int a=1;
    if (a==2)
    {
        Print("a equals 2");
    }
    else
    {
        Print("a does not equal 2");
    }
}

The code above would check to see if the variable "a" was equal to the number 2. Since it isn't, the program skips to the "else" statement and runs the code following it.

ElseIf


The "elseif" keyword provides an easy way to combine a lot of "if" statements. Here's an example:
#include "Leadwerks.h"
int main(int argc, const char *argv[])
{
    int n=2;
    if (n==1)
    {
        Print("n equals 1");
    }
    elseif (n==2)
    {
        Print("n equals 2");
    }
    elseif (n==3)
    {
        Print("n equals 3");
    }
}

The above code would print out "n equals 2" because that's the only block of code that gets executed.

Conclusion


This simple idea of branching logic forms the basis of all kinds of gameplay elements, as we will see later on in the gameplay series of tutorials. Yeah, there are more funny brackets and things in C++ but so far it's not too hard.