How to call multi argument function using ArrayList?

Question

Im trying to call this method from SDK

public ThumborUrlBuilder crop(int top, int left, int bottom, int right) {
if (top < 0) {
  throw new IllegalArgumentException("Top must be greater or equal to zero.");
}
if (left < 0) {
  throw new IllegalArgumentException("Left must be greater or equal to zero.");
}
if (bottom < 1 || bottom <= top) {
  throw new IllegalArgumentException("Bottom must be greater than zero and top.");
}
if (right < 1 || right <= left) {
  throw new IllegalArgumentException("Right must be greater than zero and left.");
}
hasCrop = true;
cropTop = top;
cropLeft = left;
cropBottom = bottom;
cropRight = right;
return this;
}

How I can call the method if the parameters are from an Array or Map like this? Is that possible?

ArrayList arrayList = [299, 296, 301, 297]
crop(arraylist)

No. Your method can accept exact 4 integer values and not array or list of integers. If you wish you can use variable length argument in method and pass an array with 4 values. But that's I think you should not do because it will allow to call method with no or any number of argument. — Akash Thakare
– Akash Thakare, Commented May 15, 2017 at 3:11

tim_yates · Accepted Answer · 2017-05-15 11:26:10Z

1

Java:

No you cant.

you will get this error:

Compilation Errors Detected
...
method crop in class Test cannot be applied to given types;
  required: int,int,int,int
  found: java.util.ArrayList<java.lang.Integer>
  reason: actual and formal argument lists differ in length

Groovy:

Yes you can. Check the sample code on groovyConsole.

def hello(int a, int b){ 
    println "$a and $b" 
}

hello(1, 2)

def param = [1,2]
hello(param)

edited May 15, 2017 at 11:26

tim_yates

172k29 gold badges359 silver badges354 bronze badges

answered May 15, 2017 at 6:30

dsharew

10.7k6 gold badges55 silver badges76 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

m0z4rt · Accepted Answer · 2017-05-15 03:57:36Z

1

public ThumborUrlBuilder crop(ArrayList params) {
    if (params.size() != 4 ){
       throw new IllegalArgumentException(...);
    }
    int top = params.get(0);
    int left = params.get(1);
    int bottom = params.get(2);
    int right = params.get(3);
    ...
}

edited May 15, 2017 at 3:57

answered May 15, 2017 at 3:13

m0z4rt

1,2452 gold badges19 silver badges26 bronze badges

1 Comment

Akash Thakare Over a year ago

This is not safe, because list with less than 4 elements can raise exception and if list has more than 4 elements other elements will be ignored.

Pim · Accepted Answer · 2017-05-15 03:18:57Z

0

This is not directly possible in Java, because the function crop requires 4 parameters.

Passing the given ArrayList into the crop function would result in an error.

You could write your own function to handle the ArrayList for you like this:

public ThumboUrlBuilder special_crop(ArrayList arraylist){
    crop(arraylist.get(0),arraylist.get(1),arraylist.get(2),arraylist.get(3));
}

answered May 15, 2017 at 3:18

Pim

5641 gold badge3 silver badges13 bronze badges

1 Comment

Andreas Over a year ago

No need to name the method something else. This is a prime example of method overloading, to make the method easier to call, by supplying various "helper" versions for different types of parameters.

Collectives™ on Stack Overflow

How to call multi argument function using ArrayList?

3 Answers 3

Java:

Groovy:

Comments

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Java:

Groovy:

Comments

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related