# Subgoals

## Section4.3Worked Example: If-Else Statements

### Subgoals for Evaluating Selection Statements.

1. Diagram which statements go together
2. For if statement, determine whether expression is true or false
3. If true – follow true branch, if false – follow else branch or do nothing if no else branch

### Subsection4.3.1

You can watch this video or read through the content below it.
Given the following declarations:
int alpha = 2, beta = 1, delta = 3, eta = 0, gamma = 0;

double omega = 2.5, theta = -1.3, kappa = 3.0, lambda = 0.0, rho = 0.0;

Evaluate these statements and determine the value of all variables used.
if (alpha > delta)
eta = alpha + 2;
else
gamma = alpha + 5;


### Subsection4.3.2SG1: Diagram which statements go together.

If no { } are present, then by default all if and else branches have only a single statement:
if (alpha > delta)
eta = alpha +2;
else
gamma = alpha + 5;


### Subsection4.3.3SG2: For if statement, determine whether true or false

First we evaluate (alpha > delta):
(2 > 3) is FALSE

### Subsection4.3.4SG3: If true, follow true branch. If false, follow else branch (OR do nothing if there is no else branch).

The condition is FALSE so we execute the else branch:
gamma = alpha + 5
= 2 + 5 = 7
Hint.
Answer: alpha = 2, beta = 1, delta = 3, eta = 0, gamma = 7