CODEWITHSUNDEEP
java
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Reputation: 125

Compare object name (reference name) with a string

How to compare name of an object to a string in Java?

For example:

class_name obj = new class_name();

and I want to compare object name obj with a string. What is the correct way to do that?

Upvotes: 3

Views: 3017

Answers (5)

Prashant Bhate
Prashant Bhate

Reputation: 11087

If you want to access Local variables and if Source code is compiled with javac -g option to retain debug info, Bytecode Library like ASM can be used to retrieve this details. See 4.3. Debug

Classes compiled with javac -g contain the name of their source file, a map- ping between source line numbers and bytecode instructions, and a mapping betwen local variable names in source code and local variable slots in bytecode. This optional information is used in debuggers and in exception stack traces when it is available

If you want to retrieve name of class level /Field variables you could use java reflection API.

Upvotes: 0

Dileep
Dileep

Reputation: 5440

You can check the Type of the Object Using instanceof keyword

Look this examples for more details

public void checkType(Object param) {
  if( param instanceof String) {
    System.out.println("param is a String");
  }
  else if( param instanceof Integer) {
    System.out.println("param is an Integer");
  }
}

I believe this is the right way to do it..!!

You can look here for more details

Upvotes: 0

arshajii
arshajii

Reputation: 129537

That can't be done directly in Java. Variable names are merely a convenience for the programmer and are not even kept track of after your code is compiled. You can instead use a Map that maps string identifiers to their corresponding objects. Or you can add a name field to your class which holds a string ("obj" in your example):

ClassName obj = new ClassName("obj");

if (obj.getName().equals(...))
    ...

(Note that I've assumed a more standard naming convention.)

Upvotes: 8

user1231232141214124
user1231232141214124

Reputation: 1349

You can get the class' class name by invoking obj.getClass(). You can't get the variable name of an object through normal means.

Upvotes: 0

Vikas V
Vikas V

Reputation: 3196

== compares object references. It finds out if the two operands point to the same object.

If you want to check if two strings contain same characters, you need to compare the strings using equals.

As to your concrete problem, it can't be done.

Upvotes: 0

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