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CSE110 Lecture 05

CSE110 Lecture 05

Principles of Programming with Java
Arithmetic Expressions
(202205)

Javier Gonzalez-Sanchez
PRO

May 23, 2017
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  1. CSE110
    Principles of Programming
    with Java
    Lecture 05:
    Arithmetic Expressions
    Javier Gonzalez-Sanchez
    [email protected]
    javiergs.engineering.asu.edu | javiergs.com
    Office Hours: By appointment

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  2. Previously:
    IDE, class, methods, variables

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  3. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 3
    Previously…

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  4. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 4
    Comments

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  5. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 5
    Comments
    • They should be included to explain the purpose of the
    program and describe processing steps
    • They do not affect how a program works
    • Java comments can take three forms:
    // this comment runs to the end of the line
    /* this comment runs to the terminating
    symbol, even across line breaks
    */
    /** this is a javadoc comment
    several lines */

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  6. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 6
    Comments
    public class MyProgram {
    }
    public static void main (String[] args) {
    }
    /**
    * comments about the class
    *
    */
    !"#$%&'
    (%&)
    /**
    * comments about the class
    */

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  7. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 7
    Comments
    public class MyProgram { //comments
    }
    // comments about the class
    *+,--'(%&)
    // Comments everywhere
    public static void main (String[] args) {
    } // here also
    // Comments could be here too

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  8. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 8
    Test Yourselves
    • What is a variable?
    • What is a data type?
    • What is a variable declaration?

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  9. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 9
    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

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  10. Expressions

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  11. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 11
    Summary
    An expression is
    a combination of one or more
    operands and their operators

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  12. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 12
    Summary
    class
    global
    variables
    methods statements
    local
    variables
    instructions
    expressions
    arithmetic
    expression
    relational
    expression
    logical
    expression
    An expression is
    a combination of one or more
    operands and their operators

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  13. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 13
    Expressions
    • 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 %

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  14. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 14
    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

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  15. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 15
    Test Yourselves
    • 17 % 4 =
    • -20 % 3 =
    • 10 % 5 =
    • 3 % 8 =

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  16. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 16
    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

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  17. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 17
    Operator Precedence

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  18. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 18
    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”);

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  19. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 19
    + 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”

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  20. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 20
    Example

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  21. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 21
    Example

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  22. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 22
    One more thing

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  23. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 23
    One more thing

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  24. Javier Gonzalez-Sanchez | CSE110 | Summer 2020 | 24
    Homework
    Read Chapter 2

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  25. CSE110 - Principles of Programming
    Javier Gonzalez-Sanchez
    [email protected]
    Summer 2022
    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.

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