How to find out if a Object is a integer or is a string or is a boolean?

java

Solution

You're pretty close, actually!

if (obj instanceof Integer)
    put(key,integerval);  
if (obj instanceof String)
    put(key,stringval);  
if (obj instanceof Boolean)
    put(key,booleanval);

From the JLS 15.20.2:

RelationalExpression `instanceof` ReferenceType

At run time, the result of the `instanceof` operator is `true` if the value of the RelationalExpression is not `null` and the reference could be cast (§15.16) to the ReferenceType without raising a `ClassCastException`. Otherwise the result is `false`.

Looking at your usage pattern, though, it looks like you may have bigger issues than this.

Problem

I have an object and I want to detect what type is, so I can call ``` if (obj isa Integer) put(key,integerval); if (obj isa String) put(key,stringval); if (obj isa Boolean) put(key,booleanval); ```

Original source