JavaFX 已从 JDK11(Oracle 的官方 JDK 和 OpenJDK)中分离出来.为了在 JDK11 中使用 JavaFX，您必须下载独立的 JavaFX11 运行时.>

I am a beginner programmer and now I want to start GUI applications in java.(as I previously worked on java too). I started reading some books on FX but its not compiling on JDK11 .. Do I need to use jdk8 or is there any way i can do it on jdk11 too?

JavaFX has become unbundled from JDK11 (both Oracle's official JDK and OpenJDK). In order to use JavaFX with JDK11, you'll have to download the standalone JavaFX11 runtime.