Intro-Java/ArrayPractice.java at master · Liebmann5/Intro-Java · GitHub

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/*
 * Chapter 7.3
 */
importjava.util.Arrays;
importjava.util.Random;

publicclassArrayPractice
{
publicstaticvoidmain(String[] args)
	{
int[] array = {1,2,3,4};
printArray(array);

int[] g = printArrayReverse(array);
System.out.println(Arrays.toString(g));

//Random nums = new Random(30);
int[] scores = randomNumbers(30);
System.out.println(Arrays.toString(scores));
//int a = scores(scores, 90, 100);
//System.out.println(a);

int[] range = newint[10];
for(inti = 0; i < range.length; i++)
 {
if(i == 0)
range[i] = inRange(scores, i, i+10);
elseif (i == 9)
range[i] = inRange(scores, i*10, i*10+11);
else
range[i] = inRange(scores, i*10, i*10+10);
 }
System.out.println(Arrays.toString(range));

/*How do the above more efficiently
 int[] counts = new int[100];
 for(int i = 0; i < scores.length; i++)
 {
 int index = scores[i];
 counts[index]++;
 }
 System.out.println(Arrays.toString(counts));*/

//try to efficiently go through the scores array
//and organize it by grades
int[] counts = newint[10];
for(inti = 0; i < scores.length; i++)
 {
intindex = 0;
if (scores[i] == 100)
counts[counts.length-1]++;
else
 {
//Int Division(/) doesn't include decimals
//and always rounds the decimals down
index = ((scores[i] % 100)/10);
counts[index]++;
 }
 }
System.out.println(Arrays.toString(counts));

//Enhanced for Loop
int[] countsMore = newint[101];
for (intscore : scores)
countsMore[score]++;
System.out.println(Arrays.toString(countsMore));

int[] countAgain = newint[10];
for(intassign : scores)
 {
//assign replaces writing scores[i]
if (assign == 100)
countAgain[countAgain.length-1]++;
else
countAgain[((assign%100)/10)]++;
 }
System.out.println(Arrays.toString(countAgain));
	}

publicstaticStringprintArray(int[] a)
	{
System.out.print("{");
for(inti = 0; i < a.length; i++)
 {
if(i == 0)
System.out.print(a[0]);
else
System.out.print(", " + a[i]);
//For a[4] why does an OutOfBounds err not occur?
//Also why is there not another comma after 4?
//YOUR DUMB! Do it!
 }
System.out.println("}");
return"}";
//Why does it not return }?
//RETURN prints nothing
	}

//To copy an array from one to another you do it this way
//int[] c = Arrays.copyOf(b, b.length); does it too
publicstaticint[] printArrayReverse(int[] b)
	{
int[] c = newint[b.length];
//int j = 0;
for(inti = b.length-1; i >= 0; i--)
 {
for (intj = 0; j <= b.length-c.length; j++)
 {
c[j] = b[i];
System.out.print(c[j]);
//break;
//j++;
 }
 }
//System.out.println();
System.out.println(Arrays.toString(c));
returnc;
	}

publicstaticint[] randomNumbers(intsize)
	{
Randomnumbers = newRandom();
int[] rando = newint[size];
for(inti = 0;i < rando.length; i++)
rando[i] = numbers.nextInt(101);
returnrando;
	}

publicstaticintinRange(int[] scores, intlow, inthigh)
	{
intcount = 0;
for(inti = 0; i < scores.length; i++)
 {
if(scores[i] < high && scores[i] >= low)
count++;
 }
returncount;
	}
}