public class ArraysExercises{
Displays all of the elements of an array (of doubles) on one line
@param array
public static void displayAll( double[] arr ){
for( int index = 0; index < arr.length; ++index){
System.out.println( arr[index] );
}
}
Makes a copy of the elements in array from startIndex to endIndex (but not including endIndex) (up to the end of the array)
@param arr
@param startIndex
@param endIndex
@return
public static int[] subset( int[] arr, int startIndex, int endIndex ){
int[] subsetArray = new int[ endIndex - startIndex ];
int subsetArrayIndex = 0;
for( int i = startIndex; i < endIndex && i < arr.length; ++i){
subsetArray[ subsetArrayIndex ] = arr[i];
subsetArrayIndex = subsetArrayIndex + 1;
}
return subsetArray;
}
Returns the average value
@param ...
@return
public static double average( double[] arr ){
double total = 0.0;
for( int index = 0; index < arr.length; ++index){
total += arr[index];
}
return total/arr.length;
}
public static void doubleValues( int[] arr){
for( int i = 0; i < arr.length; ++i){
arr[i] = arr[i]*2;
}
}
public static String[] append( String[] arr, String item ){
String[] dup = new String[ arr.length + 1 ];
for(int i = 0; i < arr.length; ++i){
dup[i] = arr[i];
}
dup[ dup.length - 1 ] = item;
return dup;
}
public static void main( String[] args ){
double[ ] milesRan = new double[ 366 ];
milesRan[0] = 3.1;
double total = 0.0;
for( int index = 0; index < 100; ++index){
total += milesRan[index];
}
System.out.println( "Average is: " + total/100.0);
displayAll( milesRan );
System.out.println( "Average for all year: " + average( milesRan) );
int[] array = {4, 1, 2, 3, 13};
System.out.println("Before:");
for( int i = 0; i < array.length; ++i){
System.out.println( array[i] );
}
doubleValues( array );
System.out.println("After:");
for( int i = 0; i < array.length; ++i){
System.out.println( array[i] );
}
displayAll( milesRan );
int[] sub = subset( array, 1, 2 );
System.out.println( "Sub:");
for( int i = 0; i < sub.length; ++i){
System.out.println( sub[i] );
}
sub = subset( array, 2, 8 );
System.out.println( "Sub:");
for( int i = 0; i < sub.length; ++i){
System.out.println( sub[i] );
}
String[] children = new String[ 3 ];
children[0] = "Emma";
children[1] = "Noah";
children[2] = "Olivia";
children = append( children, "Liam");
for( String child : children ){
System.out.println( child );
}
}
}