[PDF] Input and Formatted Output (printf) PDF

Java printf( ) Method Quick Reference

Java printf( ) Method Quick Reference. System.out.printf( “format-string” [ arg1

Java 1.5 AP Computer Science Java 1.5 Improved Output

Java 1.5. 3. Improved Output. Java 1.5 has a C style printf method printf can be used to format text output out.printf("%s " "a string"); // strings.

Input and Formatted Output (printf)

11 Feb 2020 – Put the import statement at the top of the Java file. – Create a Scanner object as shown in the first line of the main method: Scanner in = ...

The DecimalFormat Class Java has a default way of displaying

particular format. The Java API provides a class to do this called DecimalFormat. Here's a quick summary of the available printf format specifiers:.

A Type System for Format Strings

25 Jul 2014 Format string printf

Building Java Programs

Formatting text with printf. System.out.printf("format string" parameters);. A format string can contain placeholders to insert parameters:.

A Format String Checker for Java

Java supports format strings but their use is error prone Format string

Looping Paradigms System.out.printf

7 Sep 2011 Useful for indentations tabs

Untitled

printf format specifier field width. CHAPTER 2. Console Input and Output. FORMATTING OUTPUT WITH printf. Starting with version 5.0 Java includes a method

Console Input and Output

named printf that can be used to produce output in a specific format. The Java method printf is similar to the print method. Like print printf does

[PDF] Java printf( ) Method Quick Reference

Java printf( ) Method Quick Reference System out printf( “format-string” [ arg1 arg2 ] ); Format String: Composed of literals and format specifiers

[PDF] A printf format reference page (cheat sheet)

14 oct 2014 · printf formatting with Perl and Java In this cheat sheet I'm going to show all the examples using Perl but at first it might help to

[PDF] Input and Formatted Output (printf)

11 fév 2020 · To create a Scanner object we need to: – Put the import statement at the top of the Java file – Create a Scanner object as shown in the first

[PDF] JavaioPrintStreamprintf() Method Example - Tutorialspoint

PrintStream printf method is a convenience method to write a formatted string to this output stream using the specified format string and arguments Declaration

Java printf() - Print Formatted String to Console DigitalOcean

3 août 2022 · String format() returns a formatted string System out printf() also prints a formatted string to the console · printf() uses the java util

[PDF] Strings and objects; printf reading - Building Java Programs

Formatting text with printf System out printf("format string" parameters); A class is a blueprint or template for constructing objects

[PDF] Formatted Output - Pearson

Chapter I Formatted Output I 1 Introduction In this appendix we discuss the formatting features of method printf and class Formatter (package java util)

[PDF] Starting with version 50 Java includes a method named printf that

The method printf is used the same way as the method print but allows you to add formatting instructions that specify such things as the number of digits to

[PDF] (4) A popular way of formatting output in Java is the print format

(4) A popular way of formatting output in Java is the print format System out printf(“The product of d and d is d” x y x*y);

Formatting Output with printf() in Java Baeldung

6 avr 2023 · In this tutorial we'll demonstrate different examples of formatting with the printf() method The method is part of the java io

What is printf format in Java?
The Java printf function helps simplify the task of printing formatted output to the console, terminal window or log files. The Java printf function makes it easier to create informative strings of text without using String concatenation, or relying on non-standard characters that might trigger output errors.
What does %4d mean in Java?
The format specifier %4d is used for the third argument to indicate that the value should be printed using the %d format conversion with a minimum field width of 4 characters.
How to format text with printf in Java?
How to printf a Java String
1Use %s as the printf String specifier in the text string being formatted.2Use %S as the printf String specifier to output upper-case text.3Precede the letter s with a number to specify field width.4Put a negative sign after the % to left-justify the text.
To use Java printf to format double and float values with decimal place precision, follow these two rules:
1Use %f as the double specifier in the text string.2Precede the letter f with a decimal and number to specify precision.

Input and Formatted Output (printf)

CSE 1310 -Introduction to Computers and Programming

University of Texas at Arlington

12/11/2020

Book reference

•2.3 Input and Output 2

User input with Scanner

3 import java.util.Scanner; public class

Example1 {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

System.out.print

Please enter number of weeks: ");

intweeks = in.nextInt(); intdays = weeks * 7; System.out.println("There are " + days + " days in " + weeks " weeks");

There are several new things here:

-the import line. -The Scanner object. -The in.nextIntmethod. The Scannerobject allows us to obtain user input.

To create a Scannerobject, we need to:

-Put the import statement at the top of the Java file. -Create a Scanner object, as shown in the first line of the main method:

Scanner in = new Scanner(System.in);

Input •Import: java.util.Scanner •Create a Scanner object:

Scanner kb = new Scanner(System.in);

(You can use any name instead of kb. E.g: Scanner in = new Scanner(System.in); ) •E.g. read in (from the user/keyboard): •Any of the methods above for reading data in, when executed, "halt the program" to allow the user to type data (the user has control). Only after the user hits Enter the program continues to execute (the control is given back to the program). 4

Read dataand

store it as type:Methodcall (on a Scanner object named kb)Example instruction intkb.nextInt()intn = kb.nextInt(); doublekb.nextDouble() double salary = kb.nextDouble();

Stringkb.nextLine() String name = kb.nextLine();

(data until Enter, Enter dissapears)

Stringkb.next() String name = kb.next();

(data until space or Enter, Enter remains)

Entering more than one piece of data

per line intage=0; double temp=0;

String nm = "";

System.out.println

("Enter (separated by one space): age name number"); age = kb.nextInt(); nm = kb.next(); // NOT kb.nextLine() temp = kb.nextDouble();

System.out.println

("Hi " + nm + "!");

System.out.println

("The outside temperature is " + temp);

System.out.println

("Your age is " + age); 5

Sample run:

Enter (separated by one space): age name number

20 Sam 87.5

Hi Sam!

The outside temperature is 87.5

Your age is

20 next() vs nextLine()

CodeOutput

System.out.print("What is your name? ");

// nextLinereads the whole line (up to new line): name = kb.nextLine(); System.out.println("Hello " + name); What is your name? Alex Stefan

Hello Alex Stefan

System.out.print("What is your name? ");

// nextreads up to first separator (space, Enter, tab): name = kb.next(); System.out.println("Hello " + name); What is your name? Alex StefanHello Alex 6

Why nextLine() seems to not work sometimes

7 -When the user presses Enter, the corresponding symbol (%n) is recorded in the input stream. So there will be a character there for the Enter (also called new-line character: %n or \n). -nextInt(), nextDouble() and next() do NOT "eat" the Enter at the end of the line. -nextLine() DOES consume the Enter from the end of the line. -If nextLine() is used after a next()/nextInt()/nextDouble() it will just read the Enter left there from these methods. Solution: use an extra nextLine() just to consume that Enter.

CodeOutput

System.out.print("What is your name? ");

name = kb.next(); // will NOT "eat" the Enter after Alex

System.out.println("Hello " + name);

System.out.print("What is your last name? ");

last = kb.nextLine(); System.out.println("Hello " + last); What is your name? Alex

Hello Alex

What is your last name? Hello

System.out.print("What is your name? ");

name = kb.next(); will NOT "eat" the Enter after Alex

System.out.println("Hello " + name);

System.out.print("What is your last name? ");

kb.nextLine(); // it will "eat" the Enterafter Alex last = kb.nextLine();

System.out.println("Hello " + last); What is your name? AlexHello AlexWhat is your last name? StefanHello Stefan

How the output screen "works"

•You always print: -Left to right and -From top down •You can go back to the beginning of the line you are on with \r •You can NEVER go up a line -So if you need to print something that looks like a table of numbers, you must print it row -by-row (according to the desired output). You cannot print it column-by-column. •If you printed more than a screen length, it scrolls down so you always have the line you are on at the bottom. To see the earlier lines, scroll up.

•You can simulate clearing the screen by printing enough new lines to push the previous outputted text out of the visible range.

-See this image. 8

System.out.printf()

9 Code: inthours = 100; double days = 100/24.0; // used 24.0 to avoid integer division

System.out.print

("days: ");

System.out.print

(days);

Output

days: 4.166666666666667

Problem with output:

Code: inthours = 100; double days = 100/24.0; // used 24.0 to avoid integer division

System.out.print

("days: ");

System.out.print

f("%.3f",days);

Output

days: 4.167

Solution:

System.out.printf()

•Used for "formatted printing" •Uses format specifiers. They indicate the type. The format specifier must match the type of the value that will be printed. •Specify number of decimals to be displayed for real numbers: %.3f •Specify a minimum width (number of spaces) when printing that value: %10.3f •With the minimum width, text is aligned to the right by default. To align to the left use -: %-10.3f •%n -moves a new line •%% -prints the % symbol 10

Format specifierData type

%dint(Integer) %fdouble, float, (numberswith decimal values) %sString %bBoolean %cchar (a single symbol)

Specifying Width

•After the % sign, you can put a number, specifying the minimum width to be used when printing that value. For example: -%5d means "allocate at least 5 spaces for that int". -%10s means "allocate at least 10 spaces for that string". -%7f means "allocate at least 7 spaces for that double". -%7.2f means "allocate at least 7 spaces for that double, but only two after the decimal point". -%.2f means "allocate as many spaces as needed for that double, but use only two of them after the decimal point". •Use the width to print data aligned like in a table. 11

Examples

12 public class hello1 { public static void main(String[] args

System.out.printf

-10.2f%n", 18.0); // left aligned: -

System.out.printf

10.2f%n

", 20.0); // right aligned

System.out.printf

10.3f ", 10.2); // no text

System.out.printf

("%n "); // only %n

System.out.printf

10.2f%5d%n

", 15.7,3); // no text and %n

System.out.printf

10.2f%d%n

", 15.7,3 ); // no space before 3

System.out.printf

10.2f", 15.7);

System.out.printf

n%10.2f%n%5d%n ", 11.3,8);

Example Output:

Notice the effect of

10.2ffor 18.00

18.00 20.00

10.200 15.70 3

15.703

15.70 11.30 8

Looks like one number, but

2 different numbers are

printed here: 15.70 and 3

You can mix text and

[multiple pieces of ] data 13 Code:

System.out.printf

("%s is %d years old","Jane ", 23);

Output

Jane is 23 years old

The format specifiers must match the arguments in the given order. Here %s for "Jane" and %dfor 23

Escape sequences

14 public class hello1 { public static void main(String[] args

System.out.printf

some\ttext%nmoretext");

System.out.printf

nI \'m here\"\\");

System.out.printf

n"); }

Escape sequences:

%n -new line (note: use %n (platform appropriate), not \n )

\t -tab

\' -insert single quote in text

\" -insert double quote in text

\\-insert backslash in text

%% -insert % symbol in text :E.g.

System.out.printf("%%");

Output:

sometext more text

I'm here"\

Formatted Printing -References

•Java API: https://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html#syntax

•Oracle Java tutorial (brief): https://docs.oracle.com/javase/tutorial/java/data/numberformat.html

•FUN: You can also build a string (without printing it) using String.format(...). The format method works like the System.out.printf(...), but it returns a string.

String s;

s= String.format("There are %d days in %s%n", 31, "July");

System.out.println(s);

Print a table using printf

•Write a program that asks the user information for 3 cities as follows: 3 times it should ask for: -city name, -Area in kilometers (km), Next it should print a table with this information. The table will have 1 header and 3 rows (one row per city). Simulate horizontal and vertical lines in the table with |, -and + symbols. •Problem solving: -Plan how you want the interface to look like -what type will you use for each piece of data -Print the information aligned -Add horizontal and vertical lines 16

System.out.printf-build the formatting string

•System.out.printftakes 1 or more arguments. The first must be a string and it is called the formatting string . It will include specifications for formatting the text such as the reversed width for displaying certain data.

•But the formatting string is just a string and it can be built before the method (printf) is called.

•Example: the user enters a width, w, (as int) and a String, s, and the program must print the string s on w reserved spaces.

System.out.print

("Enter width: "); intw = kb.nextInt(); // assume user enters 15

System.out.print

("Enter text: ");

String s =

kb.nextLine // Assume user enters CSE 1310

String fStr= "|%" + w + "s |"; //fStris "|%10s|"

System.out.printf

(fStr, s); // Output: | CSE 1310| 17quotesdbs_dbs6.pdfusesText_12

[PDF] [PDF] Input and Formatted Output (printf)

What is printf format in Java?

What does %4d mean in Java?

How to format text with printf in Java?

How to printf a Java String

To use Java printf to format double and float values with decimal place precision, follow these two rules:

Input and Formatted Output (printf)

University of Texas at Arlington

12/11/2020

Book reference

User input with Scanner

Example1 {

Scanner in = new Scanner(System.in);

System.out.print

Please enter number of weeks: ");

There are several new things here:

To create a Scannerobject, we need to:

Scanner in = new Scanner(System.in);

Scanner kb = new Scanner(System.in);

Read dataand

Stringkb.nextLine() String name = kb.nextLine();

Stringkb.next() String name = kb.next();

Entering more than one piece of data

String nm = "";

System.out.println

System.out.println

System.out.println

System.out.println

Sample run:

Enter (separated by one space): age name number

20 Sam 87.5

The outside temperature is 87.5

Your age is

CodeOutput

System.out.print("What is your name? ");

Hello Alex Stefan

System.out.print("What is your name? ");

Why nextLine() seems to not work sometimes

CodeOutput

System.out.print("What is your name? ");

System.out.println("Hello " + name);

System.out.print("What is your last name? ");

Hello Alex

What is your last name? Hello

System.out.print("What is your name? ");

System.out.println("Hello " + name);

System.out.print("What is your last name? ");

How the output screen "works"

System.out.printf()

System.out.print

System.out.print

Output

Problem with output:

System.out.print

System.out.print

Output

Solution:

System.out.printf()

Format specifierData type

Specifying Width

Examples

System.out.printf

System.out.printf

10.2f%n

System.out.printf

System.out.printf

System.out.printf

10.2f%5d%n

System.out.printf

10.2f%d%n

System.out.printf

10.2f", 15.7);

System.out.printf

Example Output:

Notice the effect of

10.2ffor 18.00

10.200

15.70 3

15.703

Looks like one number, but

There are several new things here:

To create a Scannerobject, we need to:

\t -tab

\' -insert single quote in text

\" -insert double quote in text

\\-insert backslash in text

%% -insert % symbol in text :E.g.