Check out example codes for "java add element to existing array". It will help you in understanding the concepts better.

Code Example 1

//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;

Code Example 2

car redCar = new Car("Red");
car Garage [] = new Car [100];
Garage[0] = redCar;

Code Example 3

List<type> arr;

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