assignment_statements.md

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Day 2

Assignment Statements

Understanding how to read and use assignment statements is a critical skill in programming

Reading Assignment Statements

• Assignment statements are read from right-to-left, not from left-to-right
• Use phrases like assigns, or stores the value, instead of equals, or equal to

# the value of 5 is assigned to the variable named x
x = 5
# the current value of x(5) is added with 1
# that sum is then assigned to the variable named x
x = x + 1

# the value of 1 is assigned to the variable named x
x = 1
# the value stored in x(1) is assigned to y
# note: this does not mean that x and y will always
# store the same value
y = x

Practice Reading and Evaluating

1. What is the value of x, after the following code is executed?

   x = 2
   x = x + 3
   x = x * 2

2. What are the values of x, and y, after the following code is executed?

   x = 3
   y = x
   x = x - 7
   y = y - 1

Compound Assignment Statements

To make your code shorter, you can used compound assignment statements. These only work if the variable on the left-side of the statement has a value other than nil

Compound Statement	Long-form statement
x += 3	x = x + 3
x -= 4	x = x - 4
x /= 2	x = x / 2
x *= 8	x = x * 8

Resources

• Ada Assignment Statements Video (11:09)