java.lang.nullpointerexeption when trying to change a objects attributes

[weary pilot]

I have a java school project that is due to tomorrow. But I suddenly keep getting an error when im trying to change an objects attributes. I am working with a program called blueJ. It gives you a better overview of the project and there is no main class since you have to create (at least one) object yourself. But I have a problem. The GUI2 class has a method in which the name attribute of the player class should be changed. Now if create objects of each class and call the method by hand I get the error java.lang.nullpointerexeption in the line in which the name of the player is being changed.

Pls anwer quickly since I will get 0 points if I don't have my fully finished project by tomorrow.
Thank you in advance.

[shrewd ocean]

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[pulsar umbra]

since variables weren't initialised in constructor (or with declaration) , they are set to null automatically. You can't operate with objects that are null. you need to initialise them, like spieler1 = new Spieler("name", etc);

[weary pilot]

yes when i create the player object by hand it asks me for the name etc. and i fill it in correctly

i have also tried if it would work if I created the player with code but i got the same result

[pulsar umbra]

I'm sure you need to create spieler objects by hand

for example, you create JFrame object by hand too

fenster2 = new JFrame("round")

so you also need to create a player by hands too

[weary pilot]

no with doing it by hand i mean clicking buttons in bluej

[pulsar umbra]

I mean by coding it.

like, spieler1 = new Spieler("name", etc);.

and only after that you can use that object

[weary pilot]

i get the same error

this is what i meant by creating it by hand

[pulsar umbra]

at which line of code?

[pulsar umbra]

does it say at which line of code it gives nullpointerexcepton

[weary pilot]

yes before it was the line in which the name is changed but now its the line in which the object is created

wait nevermind

i think it worked

wait a second

I HAVE ABSOLUTELY NO CLUE WHY IT WORKS WHEN THE OBJECT IS CREATED WITH CODE INSTEAD OF BY HAND BUT I DONTZ CARE

thank you so much man

saved my sife

*life

[pulsar umbra]

you are welcome 🙂

[weary pilot]

i think that objects created by hand are somehow not recognized by java. Which means that I am absolutely fcked because my whole project is build on one class which needs to be crated by hand at the beginning

[pulsar umbra]

bluej is awful. Use at least eclipse. Intellij is better. But sometimes teachers make students use bluej. But if you don't have to use it - use at least eclipse

[weary pilot]

no we have to use it

but i think i found a way around this

ill just make an object which creates the main object and starts the game because the startgame method is in the constructor