“Introduction to Programming With Java”
nlp-ai@cse.iitb
Lecture – 5
U
MESHP
ATIL (umesh@cse.iitb.ac.in)nlp-ai@cse.iitb
• Quick recap of the syllabus covered so far.
• Solutions to previous assignments.
• Some programing practice.
• Introduction to Arrays.
Contents for Today’s Lecture
nlp-ai@cse.iitb Structure of Java Program:
class class-name {
public static void main(String args[]) { statements;
} }
Printing messages to the screen:
System.out.println(“Hello World”);
System.out.print(“Hello World”);
Recap
nlp-ai@cse.iitb Data Types:
Numbers – int (whole no.s), double (no.s with decimal point) eg. int i = 23;
double d = 33.23 Character – char
eg. char c = ‘a’;
String – String
eg. String s = “Hi”;
Boolean – boolean
eg. boolean b = false;
Variable declaration:
data-type variable-name eg. int i = 23;
Recap…
nlp-ai@cse.iitb Expression:
An expression is a combination of literals (like 100), operators (like +), variables and parentheses used to calculate a value.
eg. 2 + 6 / (2 – 9) Operators:
Arithmetic –
eg. ‘-’, ‘+’, ‘/’, ‘++’ etc.
Relational –
eg. ‘<’, ‘>=’, ‘!=’ etc.
Conditional –
eg. ‘&&’ (AND), ‘||’ (OR)
Control constructs like‘if’ and ‘if else’:
Recap…
nlp-ai@cse.iitb
Write a program that averages the synsets created for three months April, May and June. Declare and initialize variable to the synset entered for each month.
Compute the average and write out the results, something like this:
Synsets Entered for April: 12 Synsets Entered for May : 14 Synsets Entered for June: 8
Average Synset Entered: 11.333333
Assignment
nlp-ai@cse.iitb class synset {
public static void main(String args[]) { int april = 12;
int may = 14;
int june = 8;
double avg;
avg = ( april + may + june ) / 3.0;
System.out.println("Synsets Entered for April " + april);
System.out.println("Synsets Entered for May " + may);
System.out.println("Synsets Entered for June " + june);
System.out.println("Average Synset Entered " + avg);
} }
Solution
nlp-ai@cse.iitb
int a_number=1; (range is 1 to 5 both including)
Print the value in a_number in word with and without using equality (= =) operator. For example it should print “Four” if a_number contains 4.
Assignment
nlp-ai@cse.iitb class assign1 {
public static void main(String args[]) { int a_number;
a_number = 5;
if(a_number == 1) System.out.println("One");
if(a_number == 2) System.out.println("Two");
if(a_number == 3) System.out.println("Three");
if(a_number == 4) System.out.println("Four");
if(a_number == 5) System.out.println("Five");
} }
Solution
nlp-ai@cse.iitb Definition:
An array is a group/collection of variables of the same type that are referred to by a common name and an index
Examples:
• Collection of numbers
• Collection of names
• Collection of suffixes
Arrays
nlp-ai@cse.iitb Array of numbers:
Array of names:
Array of suffixes:
Examples
10 23 863 8 229
ment tion ness ves
Sholay Shaan Shakti
nlp-ai@cse.iitb
Array is like a pen box with fixed no. of slots of same size.
Analogy
nlp-ai@cse.iitb
