how to push value in array in java code example

Example 1: 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;

Example 2: how to add to an array

var ar = ['one', 'two', 'three'];
ar[3] = 'four'; // add new element to ar