• Develop code for assignment statements with expressions and determine the value that is stored in the variable as a result of these statements
  • Develop code to read input

Assignment

Assignment Statements

Time to break you of a math habit. Take a look at the code below. It’s not a full program, but don’t worry about that.

a = 7;
b = a;
a = 2;

At the end of those three lines, the value of the variable b is 7. If you thought it was 2, don’t worry about it. That’s natural math thinking. It says a = b, so shouldn’t they be equal all the time? Nope.

In programming, = takes on a different meaning, that of assignment. In each of those statements above, a value is being assigned.

  • a gets 7
  • then b gets whatever a has, so 7
  • Finally, a gets reassigned 2

Data Types in Assignments

The statement int x = 1.1; won’t compile with the reason given being possible lossy conversion from double to int. We’ll eventually cover how to convert data types, but for now be mindful matching data types when using expressions and variables. Sometimes it’s OK, like you can store an int in a double, but best to stay consistent.

Adding 1 to a Variable

Yes, this gets an entire subsection. It comes up a lot. Here’s how to do it.

x = x + 1;

This doesn’t make any sense algebraically, but if you think in terms of assignment it clears up. We are assigning x the value of whatever x is plus 1 more.