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Primitive Types ​

Why Programming? Why Java? ​

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Call System class methods to generate output to the console.

ESSENTIAL KNOWLEDGE

  • System.out.print and System.out. println display information on the computer monitor.

  • System.out.println moves the cursor to a new line after the information has been displayed, while System.out.print does not.

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Create string literals.

ESSENTIAL KNOWLEDGE

  • A string literal is enclosed in double quotes.

Variables and Data Types ​

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Identify the most appropriate data type category for a particular specification.

ESSENTIAL KNOWLEDGE

  • A type is a set of values (a domain) and a set of operations on them.

  • Data types can be categorized as either primitive or reference.

  • The primitive data types used in this course define the set of operations for numbers and Boolean values.

Expressions and Assignment Statements ​

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Evaluate arithmetic expressions in a program code.

ESSENTIAL KNOWLEDGE

  • A literal is the source code representation of a fixed value.

  • Arithmetic expressions include expressions of type int and double.

  • The arithmetic operators consist of +, −, *, /, and %.

  • An arithmetic operation that uses two int values will evaluate to an int value.

  • An arithmetic operation that uses a double value will evaluate to a double value.

  • Operators can be used to construct compound expressions.

  • During evaluation, operands are associated with operators according to operator precedence to determine how they are grouped.

  • An attempt to divide an integer by zero will result in an ArithmeticException to occur.

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Evaluate what is stored in a variable as a result of an expression with an assignment statement.

ESSENTIAL KNOWLEDGE

  • 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.

  • During execution, expressions are evaluated to produce a single value.

  • The value of an expression has a type based on the evaluation of the expression.

Compound Assignment Operators ​

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Evaluate what is stored in a variable as a result of an expression with an assignment statement.

ESSENTIAL KNOWLEDGE

  • Compound assignment operators (+=, −=, *=, /=, %=) can be used in place of the assignment operator.

  • The increment operator (++) and decrement operator (−−) are used to add 1 or subtract 1 from the stored value of a variable or an array element. The new value is assigned to the variable or array element.

Casting and Ranges of Variables ​

ENDURING UNDERSTANDING

LEARNING OBJECTIVE

Evaluate arithmetic expressions that use casting.

ESSENTIAL KNOWLEDGE

  • The casting operators (int) and (double) can be used to create a temporary value converted to a different data type.

  • Casting a double value to an int causes the digits to the right of the decimal point to be truncated.

  • Some programming code causes int values to be automatically cast (widened) to double values.

  • Values of type double can be rounded to the nearest integer by (int)(x + 0.5) or (int)(x – 0.5) for negative numbers.

  • Integer values in Java are represented by values of type int, which are stored using a finite amount (4 bytes) of memory. Therefore, an int value must be in the range from Integer.MINVALUE to Integer.MAX VALUE inclusive.

  • If an expression would evaluate to an int value outside of the allowed range, an integer overflow occurs. This could result in an incorrect value within the allowed range.