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Java Java Data Structures Organizing Data Splitting Strings

Paramvir Singh
Paramvir Singh
1,517 Points

Cascading Method calls

I was just wondering if there is any special way of reading cascading method calls so it can be easily understood by us. Like Craig tells us to think of array indexing as baby years. So, is there any neat little trick or something of that sort than can be used by us?

Hi Paramvir,

I think you've linked this question to the wrong video. I'll happily explain cascading method calls but it's hard when I have no context to base them on. If you can provide a code example or link to a video in which this is explained I'll try and elaborate further on the subject.

Daniel

Paramvir Singh
Paramvir Singh
1,517 Points

Actual I had an idea what cascading method calls were and saw Craig use it so I though if there was an easier way to visual it.

1 Answer

Okay I see, where he used String.toLowerCase().split();

Cascading methods or method chaining is a process where the method returns an object (usually the same one but not necesary) an instead of us using a standard variable declaration, assignment and then calling a method we simply call the method off the returned object without actually holding it in another variable.

This is extremely useful at times when you have an object that you may want to make multiple state changes to but you dont want to make lines and line of code.

What I sometimes do is create an object like the below

public class FancyObject{

    private final String mName;
    private String mColour;
    private int mHeight;

    public FancyObject(Srtring name){
        this.mName = name;
    }

    public setColour(String colour){
        this.colour = colour;
        return this;
    }

    public setHeight(int height){
        this.mHeight = height;
        return this;        
    }


}

public class AnotherBoringClass{

    //Standard way
    FancyObject obj;
    obj = new FancyObject("myFancyObject");
    obj.setColour("blue");
    obj.setHeight(25);


    //Using method chaining 
    FancyObject obj = new FancyObject("myFancyObject").setColour("blue").setHeight(25);

}

It's not always the best approach and sometimes calling multiple chained methods gets messy but I do really like it for things such as this and it is used lots throughout Java and the Android SDK more I find.

There is no right or wrong way it's whatever works for you. There is no easier way to know the methods unfortunately you are simply calling multiple methods off the returned object and if you are unsure it to the documentation unfortunately and if you do end up switching between multiple classes it can get confusing as to which class you're actually working on but most IDE's help with this and code completion is a god send :)

I'd wait until you move onto IntelliJ to see the real benefits of method chaining but I hope the above example shows you what is happenign behid the scenes. Normally a setter method wouldn't return anything but if instead pass back a reference to the object you can chain the methods together (or not - it's up to you).

Hope this helps some Daniel

Paramvir Singh
Paramvir Singh
1,517 Points

Thanks a lot for your help, I actually found the answer to my question. Once again thanks a lot.