Programming Language

1
Programming Language
Prepared by Amir and Luba Sapir
2
Lecture 5. Plan

• Repetition (Loops)
• While
• Do while
• For
• Methods
• Scope of variables
• Passing of Parameters
• Various Examples

3
While

• While (expression)
• statement

4
While

• condition

• true

• false

• B1

• B2

5

• import java.io.
• class Factors
• public static void main (String args) throws
• IOException
• BufferedReader stdinnew BufferedReader
• (new InputStreamReader(System.in))
• int num Integer.parseInt(stdin.readLine(
  ))
• int count1
• while (countlt(num/2))
• if ((num count)0)
• System.out.println(count)
• countcount1
• //while
• // method main
• //class Factors

6
Do While Statement

• B1

• true

• condition

• false

• B2

7

• import java.io.
• class Factors
• public static void main (String args) throws
• IOException
• BufferedReader stdinnew BufferedReader
• (new InputStreamReader(System.in))
• int num Integer.parseInt(stdin.readLine(
  ))
• int count1
• do
• if ((num count)0)
• System.out.println(count)
• countcount1
• while (countlt(num/2))
• // method main
• //class Factors

8
The For Statement

• for ( initialization test update)
• for (j1, sum0 jlt5 jj1)
• sumsumj
• System.out.println(sum)

9

• import java.io.
• class Factors
• public static void main (String args) throws
• IOException
• BufferedReader stdinnew BufferedReader
• (new InputStreamReader(System.in))
• int num Integer.parseInt(stdin.readLine(
  ))
• for (int count1 countltnum/2countcoun
  t1)
• if ((num count)0)
• System.out.println(count)
• //end of for
• // method main
• //class Factors

10

• class piramida
• final static char star''
• public static void main (String args)
• int hight 4, row1, col
• while (row lt hight)
• col1
• while (collt2hight-1)
• if ((collt(hightrow-1))(colgt
  (hight- row)))
• System.out.print(star)
• else
• System.out.print(" ")
• colcol1
• //inner while
• System.out.println( )
• rowrow1
• //while
• // method main

11

• class piramida1
• final static char star''
• public static void main (String args)
• int hight 4, row1, col1
• while (row lt hight)
• if(collt2hight-1)
• if ((collt(hightrow-1))(colgt
  (hight-row)))
• System.out.print(star)
• else
• System.out.print(" ")
• colcol1 //if
• else
• col1
• rowrow1
• System.out.println( )// else
• //while
• // method main
• // class piramida1

12
Methods

• Method is a group of statements that are given a
  name.) Procedure or function)
• Return type method-name (parameter-list)
• statement list
• int minimum (int a, int b)

13

• class Test
• public static void main (String args)
• int x5, y6, min1, min2
• min1minimum(x,y)
• min2minimum(y,x)
• System.out.prinln(min1 and min2)
• // method main
• public static int minimum (int a,int b)
• if (agtb)
• return b
• else
• return a
• // minimum
• //class Test

14
Passing parameters of primitive types
5
0
5

• By value

0
min1
min2
6
2000

• x

5

• y

1000
6
5

• b

500

• a

300
5
6

• a

• b

3000
800
15
Piramida

• Rectangle with
• A number of rows4 and columns24-1
• in a fixed row in col1..(4-row) or
  (4row)..(24-1)
• a char should be a space
  

16

• class piramida1
• final static char star'' //global constant
• public static void main (String args)
• printPiramid( )
• //method main
• public static void printPiramid( )
• int hight 4, row1, col1
• while (row lt hight)
• if(collt2hight-1)
• if ((collt(hightrow-1))(colgt
  (hight-row)))
• System.out.print(star)
• else
• System.out.print(" ")
• colcol1 //if
• else
• col1
• rowrow1
• System.out.println( )// else

17

• class piramida1
• public static void main (String args)
• int gova6 char star
• printPiramid(gova,star)
• //method main
• public static void printPiramid(int hight, char
  star)
• int row1, col1
• while (row lt hight)
• if(collt2hight-1)
• if ((collt(hightrow-1))(colgt
  (hight-row)))
• System.out.print(star)
• else
• System.out.print(" ")
• colcol1 //if
• else
• col1
• rowrow1
• System.out.println( )// else

18
More complicated example

• Sin(x)x-x3/3!x5/5!-x7/7!

19

• import java.io.
• class SinusCalk
• public static void main (String args)
  throws IOException
• BufferedReader stdin new BufferedReader
• (new InputStreamReader(System.in))
• System.out.println ("Enter degree")
• int tempInteger.parseInt
  (stdin.readLine())
• double atemp3.14/180
• System.out.println ("Enter the tolerance")
• double epsDouble.valueOf(stdin.readLine()).do
  ubleValue()
• printNow(a, temp, eps)
• //main

20

• public static void printNow(double x, int temp2,
  double diff)
• double MySinsinus(x,diff)
• System.out.println ("MySin("temp2")
  "MySin)
• System.out.println ("Ready "
  "sin("x")"Math.sin(x))
• System.out.println ("The tolerance between
  the both
• functions is "Math.abs(Math.sin(x)-MySin)
  )
• // printNow

21

• public static double sinus(double num, double
  tol)
• double sum0, prev100
• for(int i1,j0Math.abs(sum-prev)gttolii2,j
  )
• prevsum
• if ((j2)0)
• sum sumhezka(num,i)/factorial(i)
• else
• sum sum-hezka(num,i)/factorial(i)
• //for
• return sum
• // end sinus

22

• public static double hezka(double num, int
  power)
• double result1
• for(int i1(iltpower)(powergt0)i)
• result resultnum
• return result
• // end hezka
• public static long factorial (int n)
• long result1
• for(int i1iltnii1)
• result resulti
• return result
• // factorial
• // class SinusCalc