COMPUTER PROGRAMMING 2014 WEEK 6
ARRAYS
EXERCISES
(EXERCISE problems are for your understanding the
topic. Will not return as homework)
GROUP 1 ARRAY OF SIMPLE VARIABLES
import java.io.*; class
array1a { public
static void main(String args[] ) { int days_of_the_month[]; days_of_the_month=new
int[12]; days_of_the_month[0]=31; days_of_the_month[1]=28; days_of_the_month[2]=31; days_of_the_month[3]=30; days_of_the_month[4]=31; days_of_the_month[5]=30; days_of_the_month[6]=31; days_of_the_month[7]=31; days_of_the_month[8]=30; days_of_the_month[9]=31; days_of_the_month[10]=30; days_of_the_month[11]=31; System.out.println("Month
April is "+days_of_the_month[3]+" days long"); } } |
import java.io.*; class
array1b { public
static void main(String args[] ) { int
days_of_the_month[]={31,28,31,30,31,30,31,31,30,31,30,31}; System.out.println("Month
April is "+days_of_the_month[3]+" days long"); } } |
import javax.swing.*; import java.util.Locale; public class array1c { public static void main(String[] args) { int a1[]={1,2,3,4,5,6}; int a2[]={1,4,9,16,25,36}; int a3[]=new int[a2.length]; String s="array1 output : "; String s1="a1 =\n"+output(a1); s1+="a2 = \n"+output(a2); for(int i=0;i<a1.length;i++)
{a3[i]=a1[i]*a2[i];} s1+="a3 = a1*a2 \n"+output(a3); JOptionPane.showMessageDialog(null,s1,s,JOptionPane.PLAIN_MESSAGE); } public static String output(int a[]) { Locale tr=new Locale("TR"); int x=25; String s1=""; for(int i=0;i<a.length;i++) { s1+=String.format(tr," %10d
",a[i]);} s1+="\n"; return s1; } } |
import javax.swing.*; import java.util.Locale; public class array1c { public static void main(String[] args) { int a1[]={1,2,3,4,5,6}; int a2[]={1,4,9,16,25,36}; int a3[]=new int[a2.length]; String s="array1 output : "; String s1="a1 =\n"+output(a1); s1+="a2 = \n"+output(a2); for(int i=0;i<a1.length;i++)
{a3[i]=a1[i]*a2[i];} s1+="a3 = a1*a2
\n"+output(a3); JOptionPane.showMessageDialog(null,s1,s,JOptionPane.PLAIN_MESSAGE); } public static String output(int a[]) { String s1="["; for(int i=0;i<a.length;i++) { s1+=a[i]+" ";} s1+="]\n"; return s1; } } |
import javax.swing.*; import java.util.Locale; public class array1c_v1 { public static int[] multiply(int a[],int
b[]) { int c[]=new int[a.length]; if(a.length!=b.length) {System.out.println("error
wrong vector size!");} else { for(int i=0;i<c.length;i++) {c[i]=a[i]*b[i];} } return c; } public static void main(String[] args) { int a1[]={1,2,3,4,5,6}; int a2[]={1,4,9,16,25,36}; int a3[]=multiply(a1,a2); String s="array1 output : "; String s1="a1 =\n"+output(a1); s1+="a2 = \n"+output(a2); s1+="a3 = a1*a2
\n"+output(a3); JOptionPane.showMessageDialog(null,s1,s,JOptionPane.PLAIN_MESSAGE); } public static String output(int a[]) { String s1="["; for(int i=0;i<a.length;i++) { s1+=a[i]+" ";} s1+="]\n"; return s1; } } |
import javax.swing.*; class
array1d { public
static void main(String args[] ) { int
array[]={2,7,12,15,18,13,11,7,1}; String
grade[]={"FF","FD","DD","DC","CC","CB","BB","BA","AA"}; int i; String
s=""; for(i=0;i<array.length;i++) {s+=grade[i]+":
"; for(int
stars=0;stars<array[i];stars++) {s+="*";} s+="\n"; } JOptionPane.showMessageDialog(null,s); } } |
import javax.swing.*; class
array1e { public
static String toString(int[] count) { String
s=""; for(int
i=1;i<count.length;i++) {s+=i+":
"+count[i]+"\n";} return s; } public
static void main(String args[] ) { int
diecount[]=new int[7]; int
die=0; for(int
i=0;i<6000000;i++) {die=1+(int)(6*Math.random()); diecount[die]++; } JOptionPane.showMessageDialog(null,toString(diecount)); } } |
import javax.swing.*; class
array1e_v1 { // better
even if a bit more confusing! //array
diecount[0] to diecount[5] public
static String toString(int[] count) { String
s=""; for(int
i=0;i<count.length;i++) {s+=(i+1)+":
"+count[i]+"\n";} return s; } public static
void main(String args[] ) { int
diecount[]=new int[6]; int
die=0; for(int
i=0;i<6000000;i++) {die=1+(int)(6*Math.random()); diecount[die-1]++; } JOptionPane.showMessageDialog(null,toString(diecount)); } } |
import java.io.*; import javax.swing.*; class
array2 { public
static int month(String s) { String
month[]={"january","february","march","april","may","june","july",
"august","september","october","november","december"}; int i; int j=-1; for(i=0;i<12;i++) {if(s.equals(month[i]))
{j=i;break;}} return j; } public
static void main(String args[] ) { int
the_day_of_the_month[]={31,28,31,30,31,30,31,31,30,31,30,31};
String
s="The day of the month : \n"; String
s2="april"; int
i=month(s2); s+="Month
"+s2+" s "+the_day_of_the_month[i]+" days long \n"; String
s1="Array example"; JOptionPane.showMessageDialog(null,s,s1,JOptionPane.PLAIN_MESSAGE);
} } |
class
math1 { public
static void main(String args[]) { int
number[]=new number[8]; number[0]=10.0; number[1]=5.0; number[2]=7.0; number[3]=9.0; number[4]=11.0; number[5]=13.0; number[6]=14.0; number[7]=18.0; double
total=0; int i; for(i=0;i<number.length;i++) { total+=number[i]; } System.out.println("Average
= "+total/number.length); } } |
class
math2 { public
static void main(String args[]) { int
number[]={10,5,7,9,11,13,14,18}; double
total=0; int i; for(i=0;i<number.length;i++) { total+=number[i]; } System.out.println("Average
= "+total/number.length); } } |
GROUP 1 ARRAY OF CLASS OBJECTS
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HOMEWORKS (You will return
solutions of this sets as homework)
HW1: int i[]={9,4,1,0,1,4,9,16,25}
is given plot the array by using * so that plot shape
*
*
*
*
*
*
*
*
*
In order to establish
that use “*” and “ “ (empty space) characters
HW
2 A method to multiply two matrices
are given in matrix class. use multiply method in matrix class to multiply two matrices in an example
program.
HW
3 create
a static method
public
static double average(double x[])
{}
To calculate average of a
given double array and test the method in a main program
HW 4:
Formula for standard deviation is given as
where
is the average value write a static
method
public
static double stdev(double x[])
{}
To
calculate standart deviation of a given double array and test the method in a main program