CS 240 – Computer Programming I Lab Kalpa Gunaratna –

Contact  Contact by   Office hours  376 Joshi  Mondays & Wednesday 3:00 pm – 4:00 pm

Get input from key board  Scanner keyboard = new Scanner(System.in);  keyboard is the given name to the variable here. You can use any name you like. Object typenameCreate new object and assign to name

Useful Arithmetic & Relational operators  > greater than, = greater than or equal to, <= less than or equal to, etc.  Example: 5 > 6 will output false. Number 5 is not greater than 6.  Boolean operators  && - logical AND  || - logical OR  Example: x==5 && y<5, this expression outputs true if and only if value of x is 5 and value of y is less than 5.

If statements  Syntax  if ( ) { runs if is true } else { runs if is false }

If else if … if( ) { your code here } else if( ) { your code here } else { your code here }

Print statements  System.out.print()  Prints a line and stays in the current line  Sytem.out.println()  Prints a line and goes to a new line  System.out.printf(“ ”, )  Ex: System.out.printf(“%.2f \n", );

Pseudo Code  Not a Java code or any programming language  Human readable code similar to a programming language.  Uses to describe algorithms.  Example:  Algorithm – if input value is greater than 5, out put to the console a success message. Otherwise exit program.  Pseudo Code –  Get user input value x. if x is greater than 5 then out put to console “Success” else exit from program  You see that pseudo code has nothing to do with Java!  More examples : 

Flow Chart  Condition  Statement input true false

 Example If then else

sum = 0 count = 1 REPEAT IF count is even THEN sum = sum + count count = count + 1 UNTIL count > 20 DISPLAY sum Pseudo code Flow chart

 You can find useful information and helpful tips about flow charts at, 