LWJGL Forum

Programming => LWJGL Documentation => Topic started by: iamcreasy on May 22, 2018, 05:10:05

Title: Error in the getting started tutorial: window(long) is being compared to Null.
Post by: iamcreasy on May 22, 2018, 05:10:05

Hello. In the getting started tutorial available here : https://www.lwjgl.org/guide

Line 50 is the following,

Code: [Select]

if ( window == NULL )
But the variable window is declared as a primitive long in Line 17,

Code: [Select]

    private long window;
A primitive long can never be null. So is this a mistake in line 50?

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Title: Re: Error in the getting started tutorial: window(long) is being compared to Null.
Post by: KaiHH on May 22, 2018, 05:51:02

NULL is not null. NULL instead is defined as a static field whose type is long and value is 0. It should resemble http://en.cppreference.com/w/cpp/types/NULL

Title: Re: Error in the getting started tutorial: window(long) is being compared to Null.
Post by: iamcreasy on May 22, 2018, 15:40:25

Oh I see. Thank you. It's a bit confusing though.

Title: Re: Error in the getting started tutorial: window(long) is being compared to Null.
Post by: KaiHH on May 22, 2018, 17:50:53

For a Java developer, maybe. But it shows that LWJGL also tries to attract C/C++ developers to the JVM platform by making it easy to adapt the vast amounts of familiar C/C++ OpenGL/GLFW examples/tutorials to the JVM/Java. It is (almost) really only copy and paste.

Title: Re: Error in the getting started tutorial: window(long) is being compared to Null.
Post by: iamcreasy on May 22, 2018, 18:56:33

Hmm, didn't think of it in that way. Interesting observation. Thank you.