Computer Science A Unit 3

Boolean expressions and if statnts

If statements

If statements

will only run and execute when a certain condition is true; and will ignore the code if the statement isn’t true

one-way selection

Flow of control

The order in which different lines of code will run

Typically each line of code runs from top to bottom

If statements can change the sequence

Two-way selection

if -else statement, meaning there are 2 watts that the code could run, the if or the else

Multi-way selection

If-else-if statement, which only runs one of the man y different listed conditions

Boolean expression

logical operations that check for multiple conditions at once

combines 2 separate Boolean expressions into a single compound Boolean expression

statement or condition that evaluates to true of false

Truth table

used to look at all possible values of the variables, and determine the value of the whole statement

Short-circuit evaluation

When the result of a logical expression using && or || can be determined by evaluating only the first Boolean expression, the second is not evaluated

Morgan’s first Law

If both A and B are true, them the whole expression is true

Morgan’s second Law

If some part of a || statement is true, then the whole expression is true