Transcript Java Tutotrial for [NLP-AI] 2

Java
Tutotrial for [NLP-AI]
2
[email protected]
27 May 2016
1
Last Assignment
asgn1
asgn2
? Print the details in tabular format
- use tabs \t
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System.out.println("\"Can
we print '\\' with
System.out.println() statement?\"" );
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Storing data
In Java, Data can be stored as
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Numbers
2, 6.67, 0.009
Characters
‘c’, ‘p’, ‘?’, ‘2’
Strings
“data”, “Hindi language”, “$99”, “www.rediff.com”
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int1
Program
int2
// this program will declare and print a number
class int2
{
public static void main(String[] arguments)
{
int weight = 68;
System.out.println("your weight is " + weight);
}
}
//end of program
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Comments(double slash)
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Not executed
For documentation
Can be placed on any line
Anything written after // is not executed
E.g.
// this is a comment
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Used to explain/describe what is done in the
program
Good practice
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Types of numbers
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float1
int
Whole numbers like 0, 575, -345 etc.
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double
Numbers with decimal point
like 12.453, 3.432, 0.0000002
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Variable declaration
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Before using any name, it must be declared
(with its type i.e int or double).
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Needed only once in one program
Generally, done initially
Syntax
datatype name;
double total; // stores the total value
int index;
int a,b , c, sum, interest;
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Assignment
int3
int5
int a; //declaration – needed once
a = 10 ; // assignment … declared above
int a = 10; // assignment and declaration together
10 = a ; // not possible – compilation error
Left hand side is always a variable for assignment
a
10
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Storage area
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int4
Assignment…
int a , b ;
a = 4;
b = 7;
a = b;
b = a;
a = 5;
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//
//
//
//
//
//
a =? b = ?
a=4 b=?
a=4 b=7
a=7 b=7
a=7 b=7
a=5 b=7
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Character data
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char1
char2
Characters
‘a’, ‘A’, ‘c’ , ‘?’ , ‘3’ , ‘ ’
(last is the single space)
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Enclosed in single quotes
Character variable declaration
char ch;
Character assignment
ch = ‘k’;
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String data
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string1
string2
string3
Strings are sequence of characters enclosed in double quotes
Declaration
String name;
String address;
String line;
Assignment
name = “ram”;
line = “this is a line with spaces”;
name = “a”; // single character can be stored
name = “”; // empty string
The sequence of characters enclosed in double quotes, printed in println()
are also strings.
E.g. System.out.println( “Welcome ! “ );
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Practice problem
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Try to print these two figures on the screen using println and least number
of strings
*******
*****
***
*
***
*****
*******
**********
*
*
*
*
*
*
**********
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Thank you
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