• ipkpjersi@lemmy.one
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    1 year ago

    Depends on the programming language. In JavaScript, it literally means that like the key or variable does not actually exist. Whereas like in C/C++, writing random bytes to random memory addresses would result in “undefined behaviour” which means basically anything could happen.

    • crystal@feddit.de
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      1 year ago

      In Javascript you can do let a = undefined, defining the variale a as undefined.

      A significant difference to defining it as null is that typeof null == "object", while typeof undefined == "undefined".