# 1.4 Assignment Statements and Input

**Suggested Skills:** 2.A, 4.A

**LO 1.4.A** — Develop code for assignment statements with expressions and determine the value that is stored in the variable as a result of these statements.

* **1.4.A.1** — Every variable must be assigned a value before it can be used in an expression. That value must be from a compatible data type. A variable is initialized the first time it is assigned a value. Reference types can be assigned a new object or `null` if there is no object. The literal `null` is a special value used to indicate that a reference is not associated with any object.
* **1.4.A.2** — The **assignment operator** `=` allows a program to initialize or change the value stored in a variable. The value of the expression on the right is stored in the variable on the left.
  * ❌ **EXCLUSION** — The use of assignment operators inside expressions (e.g., `a = b = 4;` or `a[i += 5]`) is outside scope.
* **1.4.A.3** — During execution, an expression is evaluated to produce a single value. The value of an expression has a type based on the evaluation of the expression.

**LO 1.4.B** — Develop code to read input.

* **1.4.B.1** — Input can come in a variety of forms, such as tactile, audio, visual, or text. The `Scanner` class is one way to obtain text input from the keyboard.
  * ❌ **EXCLUSION** — Any specific form of input from the user is outside scope.