Chapter 9. Control Statements
Control statements allow us to control the flow of our programming and cause different things to happen depending on the values of tests. Tests result in a logical, TRUE, or FALSE, which is used in if-like statements. The main control statements are if, else, ifelse and switch.
9.1. if and else
The most common test is the if command. It essentially says: If something is TRUE, then perform some action; otherwise, do not perform that action. The thing we are testing goes inside parentheses following the if command. The most basic checks are equal to (==), less than (<), less than or equal to (<=), greater than (>), greater than or equal to (>=) and not equal (!=).
If these tests pass they result in TRUE, and if they ...
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