Difference between if and if else and if else if?

if (5 == 5)
{
// some code
}

In this case, if 5 is equal to 5, then the code inside the ¬
if block is executed.

if (5 == 4)
{
// some code
}
else
{
// some other code
}

In this case, if 5 is equal to 4, then the code inside the if block is executed.
If 5 is NOT equal to 4, then the code inside the else block is executed.

if (5 == 4)
{
// some code
}
else if (5 == 6)
{
// some other code
}

In this case, if 5 is equal to 4, then the code inside the
if block is executed.
If 5 is not equal to 4, then the code in the else if block will only get executed if 5 is equal to 6.

Hope this helps.