17

I'm looking for a way to get the name of an object instance at run-time. Is it possible to to determine the class name (as a string) of an instance? i.e. is there an Apex equivalent of the Java myInstance.getClass().getName() or any tricks to achieve just that?

Phil Hawthorn
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  • String.valueOf(myInstance) will get you pretty close - works with built in classes too... 
    class MyClass {}

    System.debug(String.valueOf(new MyClass()));

    //MyClass:[]

    System.debug(String.valueOf(new PageReference('')));

    //System.PageReference[]

     – Matt and Neil Jan 16 '13 at 16:36
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    Yes - thanks, only trouble is with that if someone has overridden the toString() method in the class it may return something other than the class name, i.e. you can't always rely on it. – Phil Hawthorn Jan 16 '13 at 16:40
  • I thought you owned all the classes :P – Matt and Neil Jan 16 '13 at 16:56
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    @user320 - lol, yes I do and I know that I have overridden toString() (for a good reason too) and that it won't work in my use case. – Phil Hawthorn Jan 16 '13 at 17:05
  • @user320 your idea works well unless myInstance has a value of null. How would one work around this? – cropredy Dec 26 '13 at 22:15
  • If myInstance is null, I think only you can know what you intended to hand it it. What's your requirement exactly? Could be a good question to ask. – Matt and Neil Dec 26 '13 at 22:42

4 Answers4

13

instanceOf verifies at runtime whether an object is actually an instance of a class...but you would have to write the conditions to check for them all. Also getSObjectType will describe an sObject.

tomlogic
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fourq
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    Thanks, actually I've just realised that since I own all of the classes I'm interested in I can implement my own getName() method. – Phil Hawthorn Oct 16 '12 at 19:24
7

Voting for the idea Method to get the Type of an Object (also Primitive Type not only SObject) would be a good long term solution.

Daniel Ballinger
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1

From Trailhead's Apex Recipes, covers Inner Classes as well.

/**
     * @description It can be useful to know what the type of an object
     * is at runtime. This is especially useful when you're dynamically
     * instantiating objects in code from the name of a class.
     *
     * I'm not generally a fan of relying on an exception to make logic
     * decisions, but in this case I'll make an exception as this is the
     * cleanest method I've yet found for efficently determining an objects
     * class name that covers edge cases where the object is of an inner class'
     * type.
     *
     * This method parses a TypeException for the true name of a class.
     * It generates the exception by forcing a cast from the Object parameter
     * to DateTime. If no typeException occurs, we know it's a dateTime object.
     * @param obj
     * @return      `String`
     */
    public static String getUnkownObjectType(Object obj) {
        String result = 'DateTime';
        try {
            DateTime typeCheck = (DateTime) obj;
        } catch (System.TypeException expectedTypeException) {
            String message = expectedTypeException.getMessage()
                .substringAfter('Invalid conversion from runtime type ');
            result = message.substringBefore(' to Datetime');
        }

    return result;
}
Christian Szandor Knapp
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0

You can use something like below:

String.valueOf(this).substring(0,String.valueOf(this).indexOf(':'));

Sources
@pbattisson's Ans
@Matthew's Ans in SF blog

Community
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Pradeepkumar'2552866
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