RANDOM QUESTION

[glossy forge]

I'll just post some question about Java here

[astral shore]

⌛ This post has been reserved for your question.

Hey @glossy forge! Please use /close or the Close Post button above when your problem is solved. Please remember to follow the help guidelines. This post will be automatically marked as dormant after 720 minutes of inactivity.

TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.

[glossy forge]

Hey so I was wondering

Why can I do that

        char[] testChar = new char[1];
        testChar = input.next().toCharArray();

        System.out.println(testChar);

But not that

        char[] testChar = new char[0];
        testChar[0] = input.next().toCharArray();
        System.out.println(testChar);

I triend changing toCharArray() but I didnt find a way so I was just wondering

[young flame]

Because in the first example you are reassigning the whole testChar variable to another char[] array.
In the second case you are trying to assign an array to a single char.

[glossy forge]

Oh so toCharArray() resize the whole thing, didnt know that

Good to know thank you

[astral shore]

If you are finished with your post, please close it.
If you are not, please ignore this message.
Note that you will not be able to send further messages here after this post have been closed but you will be able to create new posts.

[young flame]

It's not resizing, it is overwriting the variable with a new array.

[worthy grove]

To different datatypes

One is a char array, the other a singular char

[vital oyster]

You can also do char[] testChar = input.next().toCharArray();

[glossy forge]

and toCharArray will "choose" the size of my array ig ?

[vital oyster]

or if you want to overwrite an individual character:

char[] testChar = new char[1];
testChar[0] = input.next().toCharArray()[0];

or

char[] testChar = new char[1];
testChar[0] = input.next().charAt(0);

[vital oyster]

toCharArray creates a new array which testChar is assigned to

new char[1] creates a char[] and String#toCharArray does so as well

[glossy forge]

okok, thats some wierd behavior to me id never figure that out by myself

[vital oyster]

arrays are just objects

[young flame]

This is not like in C where you have to preallocate some buffer and then fill it/write to it.
In your code the new char[1] is thrown away after the toCharArray() assignment.

[cerulean raft]

testChar is not an array. It is a reference to an array.

toCharArray() is returning a reference to a new array. so you're just replacing one reference with another.

This behaviour of the assignment operator is the same for all types in Java.

The code should probably have been (unless you can be certain the next token isn't empty - and we're ignoring the fact that there may not be a next token)

String nextToken = input.next();
if (!nextToken.isEmpty()) {
    char firstChar = nextToken.charAt(0);
    ...
}

[glossy forge]

Ok that make sense

[astral shore]

💤 Post marked as dormant

This post has been inactive for over 720 minutes, thus, it has been archived.
If your question was not answered yet, feel free to re-open this post or create a new one.
In case your post is not getting any attention, you can try to use /help ping.
Warning: abusing this will result in moderative actions taken against you.