“Introduction to Programming With Java” Lecture – 5 UMESH PATIL (umesh@cse.iitb.ac.in) nlp-ai@cse.iitb

Contents for Today’s Lecture Quick recap of the syllabus covered so far. Solutions to previous assignments. Some programing practice. Introduction to Arrays. nlp-ai@cse.iitb

Recap 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”); nlp-ai@cse.iitb

Recap… 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; nlp-ai@cse.iitb

Recap… 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’: nlp-ai@cse.iitb

Assignment 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 nlp-ai@cse.iitb

Solution 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); } } nlp-ai@cse.iitb

Assignment 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. nlp-ai@cse.iitb

Solution 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"); } } nlp-ai@cse.iitb

Arrays 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 nlp-ai@cse.iitb

Examples 10 23 863 8 229 Sholay Shaan Shakti ment tion ness ves Array of numbers: Array of names: Array of suffixes: 10 23 863 8 229 Sholay Shaan Shakti ment tion ness ves nlp-ai@cse.iitb

Analogy Array is like a pen box with fixed no. of slots of same size. nlp-ai@cse.iitb

End Thank you… nlp-ai@cse.iitb