3 - Input Output

Embed Size (px)

Citation preview

  • 8/10/2019 3 - Input Output

    1/45

    INPUT AND OUTPUT PROCESS

  • 8/10/2019 3 - Input Output

    2/45

    Aim

    To introduce student to input and output

    concept in C programming

    Objective

    Student will be able to : Understand and identify the usage

    of input functions and operations

    Understand and identify the usage

    of output functions and operations Write C program using input and

    output operations.

    http://tafmaster.com/taf/496/250924/
  • 8/10/2019 3 - Input Output

    3/45

    Chap 4

    Introduction

    printf() function

    scanf() function

    Other I/O functions

    Formatting Output

    Topics in Chapter 4

  • 8/10/2019 3 - Input Output

    4/45

    Input and output are two importantoperations in computer programming.

    Data will be read as input to computerand will be processed as output.

    Input and output (I/O) can be doneeither through interactive or file batch

    processing.

    Introduction

  • 8/10/2019 3 - Input Output

    5/45

    operation

    input output

    scanf() function printf()function

    Read data (input) Write out data (output)

    use use

    includeInclude

    Input/Output

  • 8/10/2019 3 - Input Output

    6/45

    printf ) function

    printf()

    Write out data and display as output

    Send data to output device regarding to a

    given format

    printf(output_format,print_list);

    printf(First example);

    printf(The bread price is RM %lf,price);

    function

    format

    exampleOutput

    Output

  • 8/10/2019 3 - Input Output

    7/45

    printf ) function

    continued..

    output_format

    text

    placeholder

    combination

    print_listvariable

    constant

    expression

    function_name

    printf(output_format,print_list);format

    may

    Consist of

    mayConsist of

  • 8/10/2019 3 - Input Output

    8/45

    Example 1:

    printf(Universiti Tun Hussein Onn Malaysia);

    Output:

    Universiti Tun Hussein Onn Malaysia

    printf ) function

    continued..

    Format output text/string

  • 8/10/2019 3 - Input Output

    9/45

    Example 2:

    printf(%lf, salary);

    Format output- placeholdervariable

    Output:

    printf ) function

    continued..

  • 8/10/2019 3 - Input Output

    10/45

    Example 3:

    printf(Monthly salary is RM %lf, salary);

    Output format -Text

    placeholder

    variable

    Output:

    Monthly salary is RM

    printf ) function

    continued..

  • 8/10/2019 3 - Input Output

    11/45

    Example 4:

    const float porosity 16.78;

    printf(The porosity of sand = %lf , porosity);

    Output format -Text

    The porosity of sand = 16.78000

    Output:

    printf ) function

    continued..

    constant

    placeholder

  • 8/10/2019 3 - Input Output

    12/45

    Exercise

    What are the output produced from the following statements?

    1.printf(Welcome to C programming world!>);

    2.printf(Now );

    printf(See );

    printf(Heart );

    3.printf(DIT 1064\n);

    printf(Programming Principle);

    pr in t f () funct ion

    (continued..)

  • 8/10/2019 3 - Input Output

    13/45

    escape Character

    functionTo tell the compileradditional formattingto be performed with theprintf()function

    Character Exaplaination

    \n New line

    \t Tab

    \a Beep sound

    pr in t f () funct ion (continued..)

  • 8/10/2019 3 - Input Output

    14/45

    Placeholder

    functionA symbol beginning with % in a format string that

    indicates where to display the output value

    format Using percent symbol (%) followed by characterwhich represent particular data type

    Placeholder Output to be print%d Integer number

    %lf Floating number

    %c Character

    %s String

    pr in t f () funct ion (continued..)

  • 8/10/2019 3 - Input Output

    15/45

    char huruf1, huruf2;

    huruf1 = B;

    huruf2 = P;

    printf(%c %c %c, A, B, U);

    printf(\nI live in %c%c,huruf1,huruf2);

    Example 5 (Printing character value ) :

    Output:

    ABU

    I live in BP

    pr in t f () funct ion (continued..)

  • 8/10/2019 3 - Input Output

    16/45

    int number1, number2;

    printf(My house number is %d, 26);

    number2=10;

    printf(\n\tNumber %d and %d,number1,number2);

    number2=2;

    number1= 15;

    printf(Number %d and %d,number2,number1);

    Example 6 (Printing integer value) :

    Output:

    My house number is 26

    Number and 10Number 2 and 15

    pr in t f () funct ion (continued..)

  • 8/10/2019 3 - Input Output

    17/45

    double sahih1, sahih2;

    printf(The value of pi is %lf, 3.142);sahih1= 23.46;

    printf(\nThe value of sahih1 is %lf,sahih1);

    sahih2= 15.78;

    printf(\tThe value of sahih2 is %lf,sahih2);

    Example 6 (Printing floating point number) :

    Output:

    The value of pi ialah 3.142

    The value of sahih1 is 23.46 The value of sahih2 is 15.78

    pr in t f () funct ion (continued..)

  • 8/10/2019 3 - Input Output

    18/45

  • 8/10/2019 3 - Input Output

    19/45

    scanf ) function

    scanf()Read data with specified

    format

    Read input from keyboard

    scanf(input_format,&variable_list);

    scanf(%d,&nom);

    scanf(%s %d %lf,&name,&age,&weight);

    function

    format

    example

  • 8/10/2019 3 - Input Output

    20/45

    scanf ) function continued..)

    placeholder

    variable_list variableMust consist

    input_formatConsists of example

    %d @ %c @%lf

    constantexpression function

    Not allowed!!!

    & symbol

    Called as ampersand

    Variable address/location reference

  • 8/10/2019 3 - Input Output

    21/45

    Example1:

    scanf(%lf %d %c,&float_num, &num,&letter);

    Placeholder

    Every variables to be used in the program MUSTbe declaredfirst!!!

    Variable

    The above statement is valid!

    Important Note!!!!!

    scanf() func t ion (cont in ued..)

    Faculty of Information Technology & Multimedia

  • 8/10/2019 3 - Input Output

    22/45

    Example 2:

    scanf( %d , 15);

    Placeholder Constant value

    The above statement is INVALID!

    scanf( %lf , &price + 0.05);

    Conversion character Expression

    The above statement is INVALID!

    scanf() funct ion (cont inued..)

  • 8/10/2019 3 - Input Output

    23/45

    Example 3(program code):

    #include

    void main()

    { int semester;

    float CPA;

    printf(Enter the semester : );

    scanf(%d, &semester);

    printf(\nEnter your CPA : );

    scanf(%lf,&CPA);printf(\nYour CPA for semester %d is %f,semester,CPA);

    }

    ?

    ?

    ?

    scanf() fun ct ion (cont inued..)

  • 8/10/2019 3 - Input Output

    24/45

    Output:

    Enter the semester : 3

    Enter your CPA : 3.45

    Your CPA for semester 3 is 3.45

    scanf() func t ion (cont in ued..)

  • 8/10/2019 3 - Input Output

    25/45

    1).Write the scanf()statement to accept the following type of variables:

    a. char jantina;

    b. float berat;

    c. int tempoh;

    2).State whether the following scanf()statements is VALID or INVALID.

    Given the following declaration:

    int a, b;

    char c;

    a) scanf(%d, &a + b);

    b) scanf(%c, &c);

    c) scanf(%d,&a,&b);

    Exercise

    scanf() func t ion (cont in ued..)

  • 8/10/2019 3 - Input Output

    26/45

    Other I/O functions

    There are some functions can be used in the input andouput operations in C programming such as:

    getchar() and putchar() function

    getch() dan putch() function

    gets() dan puts() function

  • 8/10/2019 3 - Input Output

    27/45

    getchar()

    To read any input from input device

    as character data type

    variable= getchar();

    char letter;

    printf(Enter one letter>>);letter= getchar();

    function

    format

    example usage

    Other I/O functions

  • 8/10/2019 3 - Input Output

    28/45

    putchar()

    To display output in a single character

    value

    putchar(variable);

    printf(The input letter is );

    putchar(letter);

    function

    format

    example usage

    Other I/O functions

  • 8/10/2019 3 - Input Output

    29/45

    Other I/O functions

    #include

    void main()

    { char letter;

    printf(Enter one letter : );

    letter = getchar();

    printf(The input letter is\t);

    putchar(letter);

    }

    Example 1: getchar() and putchar()

    Enter one letter :eThe input letter is e

  • 8/10/2019 3 - Input Output

    30/45

    Other I/O functions

    #include

    void main(){ int number;

    printf(Enter one number : );

    number = getchar();

    printf(The input number is %d\n,number);putchar(number);

    }

    Example 2: getchar() and putchar()

    Enter one number :123The input number is 49

    1

    However, we can also program like this :

  • 8/10/2019 3 - Input Output

    31/45

    getch()

    To read an input and terminate the

    program automatically

    variable= getch();

    char letter;printf(Enter one letter >>);

    letter= getch();

    function

    format

    example

    Other I/O functions

    getch() have same function like getchar(), but different action

  • 8/10/2019 3 - Input Output

    32/45

    Other I/O functions

    #include

    void main(){ int number;

    printf(Enter one number : );

    number = getchar();

    printf(The input number is %d\n,number);getch();

    }

    Example 3: getch()We can use getch() to hold user screen, and terminate once

    any input is read

  • 8/10/2019 3 - Input Output

    33/45

    putch()

    To display output , have similar function as

    putchar

    putch (variable);

    printf(The input letter is );putch(letter);

    function

    format

    example

    5.5 Other I/O functions

  • 8/10/2019 3 - Input Output

    34/45

    gets()To read string input from input device

    gets(variable);

    char name[20];printf(Enter your name >>);gets(name);

    function

    format

    example

    Other I/O functions

  • 8/10/2019 3 - Input Output

    35/45

    Other I/O functions

    #include

    void main(){ char name[20];

    printf(Enter your name : );

    scanf(%s,&name);

    printf(Your name is %s ,name);getch();

    }

    Example 4: gets()If we use scanf() function to read string input, it will only takes

    the first data between two words (if any)

    Enter your name: Siti AminahYour name is Siti

  • 8/10/2019 3 - Input Output

    36/45

    Other I/O functions

    #include

    void main(){ char name[20];

    printf(Enter your name : );

    gets(name);

    printf(Your name is %s\n,name);getch();

    }

    Example 5: gets()If we use gets() function to read string input, it will takes all the

    data including space between two words (if any)

    Enter your name: Siti AminahYour name is Siti Aminah

  • 8/10/2019 3 - Input Output

    37/45

    puts()To display string output to output device

    puts (variable);

    printf(Your name is );puts(name);

    functions

    format

    example

    Other I/O functions

  • 8/10/2019 3 - Input Output

    38/45

    formattingInteger

    To format the display of an integer

    value

    %spaced

    Use the integer formatting in theoutput statement

    functions

    format

    Where to use?

    Formatting Output

    How it works? Provide spaces according to formattingPut the value to display starting from right to leftsideIf there issign in the formatting, values willbe printed starting from left to right side

  • 8/10/2019 3 - Input Output

    39/45

    FormattingOutput

    Formatting Integer

    exampleprintf(%3d,123);

    output123

    printf(%5d,123);output

    _ _123

    printf(%10d,123);output

    _ _ _ _ _ _ _123

    printf(%-6d,123);output

    123_ _ _

    printf(%-4d%4d,123,456);output

    123_ _456

    Assume _ isan empty

    space

    example

    example

    example

    example

  • 8/10/2019 3 - Input Output

    40/45

    Formatting Output

    #include

    void main()

    {printf(%d ,123);printf(\n%3d ,123);

    printf(\n%5d ,123);

    print(\n%10d,123);

    print(\n%-6d,123);

    print(\n%-4d%d4d,123,456);}

    Example 1: Formatting Integer

    Output?

  • 8/10/2019 3 - Input Output

    41/45

    FormattingFloatingnumber

    To format the display of the floating

    number value

    %precisionf

    Use in the output statement

    functions

    format

    Where to use?

    Formatting Output

    How it works? Provide spaces according to formattingPut the value to display starting from right to leftsideIf there issign in the formatting, values willbe printed starting from left to right side

  • 8/10/2019 3 - Input Output

    42/45

    Formatting Floating numberformat

    %precisionf

    exampleprintf(%10f,57.78);

    output_57.780000

    example

    printf(%15f,57.78);output

    _ _ _ _ _ _57.780000

    example

    printf(%-10f,57.78);output

    57.780000_

    exampleprintf(%15f,57.78);

    output57.780000_ _ _ _ _ _

    Spaces is including floating point

    Formatting Output

  • 8/10/2019 3 - Input Output

    43/45

    Formatting Output (cont..)

    Formatting characterformat

    %precisionc

    example char letter = A;printf(%c,letter);printf(%2c,letter);printf(%-5c,letter);

    A_AA_ _ _ _

    output

  • 8/10/2019 3 - Input Output

    44/45

    Formatting Stringformat

    %precisions

    char ayat[] =KUITTHO PARIT RAJAprintf(%s,ayat);

    printf(%4s,ayat);printf(%22s,ayat);printf(%.7s,ayat);printf(%-20.13s,ayat);

    KUITTHO PARIT RAJAKUITTHO PARIT RAJA_ _ _ _KUITTHO PARIT RAJAKUITTHOKUITTHO PARIT_ _ _ _ _ _ _

    output

    example

    Formatting Output (cont..)

  • 8/10/2019 3 - Input Output

    45/45

    1. What is the output of this statement?

    printf(%8.5s,BIT 1033)

    2.State the output of these statements:

    float h = 253.7654;

    int g=6789;

    printf(%5d %5.1f ,g,h);

    printf(%10d %10.3f ,g,h);

    printf(%-7d %-7.5f ,g,h);

    Exercise

    Formatting Output (cont..)