Implementation principle of automatic capacity expansion mechanism of ArrayList

ArrayList Is an array structure storage container , By default, the array length is 10 individual , You can also create ArrayList The initial length of the object is specified as it continues in the program ArrayList When more than ten data are added ,ArrayList There is not enough capacity to store subsequent data , Now ArrayList Automatic capacity expansion mechanism will be triggered , The process of automatic capacity expansion mechanism is

• First, create a new data. The length of this array is the length of the original array 1.5 times
• And then use Arrays.copyOf Method copies the data in the old array to the new array

After the expansion is completed, add the elements that need to be added to the new array , So as to complete the process of dynamic capacity expansion