performance - Does an unused import declaration eat memory, in Java? -

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does unused import - import android.widget.relativelayout; eat memory? want know how or valuable? maybe stupid question, haven't found answer.

no don't take memory. imports used compiler resolve class names @ compile time.

compiler changes each class name qualified name. , removes import statement. so, import statement doesn't make byte code.

the issue can come wildcard import namespace conflict, i.e., when 2 types same name defined in 2 different packages, importing packages wildcards cause name conflict type used.

to see how compiler replaces import statement, can generate byte code of class using javap command. consider below code:

import java.util.*; import java.util.regex.*;  public class test {     public static void main(string[] args) {      } }

just compile above code, , check byte code using following command:

javap test

it gives out following output:

public class test {   public test();   public static void main(java.lang.string[]); }

so, can see string type replaced it's qualified name java.lang.string, , there no import statement in byte code.


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