201707 CSE110 Lecture 04
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This document discusses primitive data types in Java, including integer, floating point, character, and boolean types. It describes the size and value ranges of each type, as well as escape sequences for characters. The document also covers arithmetic, relational, and logical expressions used to evaluate values, and the operator precedence rules that determine the order of operations in expressions.
201707 CSE110 Lecture 04
- 1. CSE110 Principles of Programming with Java Lecture 04: Primitive Data Types Javier Gonzalez-Sanchez javiergs@asu.edu javiergs.engineering.asu.edu Office Hours: By appointment
- 2. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 2 Summary class global variables methods statements instructions local variables
- 3. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 3 Previously … § There are exactly eight primitive data types in Java § Four of them represent integers: byte, short, int, long § Two of them represent floating point numbers: float, double § One of them represents characters: char § And one of them represents boolean values: boolean
- 4. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 4 Data Types The difference between the various numeric primitive types is their size, and therefore the values they can store: Type Size Min Value Max Value byte 8 bits -128 127 short 16 bits -32,768 32,767 int 32 bits -2^31 2^31 - 1 long 64 bits -2^63 2^63 - 1 float 32 bits +/- 3.4 x 1038 with 7 significant digits double 64 bits +/- 1.7 x 10308 with 15 significant digits
- 5. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 5 char • A char variable stores a single character from the Unicode character set • The Unicode character set uses 16 bits per character, allowing for 65,536 unique characters • It is an international character set, containing symbols and characters from many world languages • Character literals are delimited by single quotes: 'a' 'X' '7' '$' ',' 'n'
- 6. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 6 Escape Sequences Escape Sequence Meaning b backspace t tab n newline ” double quote ’ single quote backslash
- 7. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 7 boolean • A boolean value – only 2 values, true or false • The reserved words true and false are the only valid values for a boolean type boolean done = false; boolean success; success = true;
- 9. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 9 Summary class global variables methods statements local variables instructions expressions arithmetic expression relational expression logical expression
- 10. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 10 Expressions • An expression is a combination of one or more operands and their operators • Arithmetic expressions compute numeric results and make use of the arithmetic operators: o Addition + o Subtraction – o Minus Unary – o Multiplication * o Division / o Remainder %
- 11. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 11 Integer Division and Remainder • Dividend / Divisor = Quotient and Remainder • Dividend = (Divisor x Quotient) + Remainder • If both operands to the division operator (/) are integers, the result is an integer (the fractional part is discarded) 14 / 3 equals 4 14 % 3 equals 2 8 / 12 equals 0 8 % 12 equals 8
- 12. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 12 Test Yourselves • 17 % 4 = • -20 % 3 = • 10 % 5 = • 3 % 8 =
- 13. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 13 Operator Precedence • Operators have a well-defined precedence which determines the order in which they are evaluated • Multiplication, division, and remainder are evaluated prior to addition, subtraction, and string concatenation • Arithmetic operators with the same precedence are evaluated from left to right • Parentheses can be used to force the evaluation order
- 14. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 14 Operator Precedence
- 15. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 15 String Concatenation • The plus operator (+) is used to concatenate (append) strings: “Hello” + “ World” • To break a string into two parts in two lines, we need to close with a double quote and use + sign to concatenate (append): System.out.println(“ASU is “ + “in Arizona”);
- 16. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 16 + operator • If two operands of + are numbers, it performs an arithmetic addition. • If at least one of operands of + is a string, it performs a string concatenation. • Examples: o 2 + 3 will be 5 o 2 + “ apples” will be “2 apples” o “number ” + 5 will be “number 5” o “we have “ + 2 + 3 will be “we have 23” o “we have “ + (2 + 3) will be “we have 5”
- 17. Javier Gonzalez-Sanchez | CSE110 | Summer 2017 | 17 Homework Read Chapter 2
- 18. CSE110 - Principles of Programming Javier Gonzalez-Sanchez javiergs@asu.edu Summer 2017 Disclaimer. These slides can only be used as study material for the class CSE110 at ASU. They cannot be distributed or used for another purpose.