ArrayList & HashMap Resizing Explained

The resizing mechanism of an ArrayList checks the current number of elements when adding new elements to see if the capacity limit has been reached. If it has, a new array is created and the elements from the original array are copied into it, updating the capacity. Typically, the capacity of the new array is 1.5 times the capacity of the original array.

The resizing mechanism of a HashMap involves checking if the number of elements exceeds a certain threshold (default 0.75 times the capacity) when adding elements. If this threshold is reached, a new array is created, existing elements are redistributed to the new array, and the capacity is increased. Typically, the capacity of the new array is double that of the original array.