Through ArrayList is it possible to pass multiple data type? If yes then need a code to demonstrate-CodePudding

i have multiple data type like eg. {10, 12.5, 20, 50, "abcd", xyz} So, i want to pass these data type through ArrayList and then filter only the integer value.

If this can be done then can any of you please provide a sample code to demonstrate it. If no, then what's the reason.

Thanks in advance

So, i assume that this can be done by creating an object of arraylist. ArrayList<Object> list = new ArrayList <>(); And then can add all these values using list.add();

But then in this how can we filter integer after adding the values is where i got stuck

CodePudding user response：

Well, you must indeed create a list which accepts both Strings and Integers. The only way is to indeed create a List<Object>.

In order to retrieve the integer values, you could just test whether the contained object is of a certain type:

for (var element : list) {
    if (element instanceof Integer) {
        // Do something with the value
    }
}

Or using streams:

list.stream()
    .filter(element -> element instanceof Integer)
    // or .filter(Integer.class::isInstance)
    .forEach(element -> {
        // Do something with the value
    });

CodePudding user response：

First part of your problem is right, just create an ArrayList<Object>

Then, try this:

ArrayList<Integer> intList = new ArrayList<Integer>();
for(Object o : list){
 try{
    intList.add(Integer.parseInt(o.toString()))
 }catch(NumberFormatException e) {
    //optional code
 }
}

CodePudding user response：

 List<Object> list= new ArrayList<>();
    list.add(1);// interger
    list.add(11.00);// Double
    list.add("Strings");//String
    System.out.println(list);