How to take array from user without initializing it's size?

Answer 1

For example:
while(scanner.hasNextLine()){... your code ...}

Answer 2

According me.., array initialization, Only 2 ways :

Ex: 1

int arr[] = new int[ 10] ;

Ex2 :
int arr[] = { 1,2,3,4,5} ;

Answer 3

I guess you are looking for this
https://stackoverflow.com/a/61478968/12512406