JAVA

java add element to existing array

//original array
String[] rgb = new String[] {"red", "green"};
//new array with one more length
String[] rgb2 = new String[rgb.length + 1];
//copy the old in the new array
System.arraycopy(rgb, 0, rgb2, 0, rgb.length);
//add element to new array
rgb2[rgb.length] = "blue";
//optional: set old array to new array
rgb = rgb2;

java add values to array

// If you read array of unknown length, from console
// and you want to put numbers into array of fixed length
long[] array = Arrays.stream(scanner.nextLine().split(" "))
                .mapToLong(Long::parseLong)
                .toArray();

int[] array = Arrays.stream(scanner.nextLine().split(" "))
                .mapToInt(Integer::parseInt)
                .toArray();