Basic If else statements

by Rachael_C September 9th 2014, 02:29

The if statement allows you to control if a program enters a section of code or not based on whether a given condition is true or false. One of the important functions of the if statement is that it allows the program to select an action based upon the user's input。

If statements allow the flow of the program to be changed, and so they allow algorithms and more interesting code。

Here are the relational operators:
>     greater than
<     less than
>=    greater than or equal
<=    less than or equal
==    equal to
!=    not equal to

If
The structure of an if statement is as follows:

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Else
Sometimes when the condition in an if statement evaluates to false, it would be nice to execute some code instead of the code executed when the statement evaluates to true. The "else" statement effectively says that whatever code after it is executed if the if statement is FALSE.
The structure of an else statement is as follows:

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Else If
Another use of else is when there are multiple conditional statements that may all evaluate to true, yet you want only one if statement's body to execute. You can use an "else if" statement following an if statement and its body.

The structure of an if else is as follows:

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Here’s a simple program:

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