The following expression compiles:
Object oa = new float[20];
How is this expression valid?
As per my opinion, the correct syntax would be
Object [] oa = new float[20];
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1Arrays are Objects in Java.ChiefTwoPencils– ChiefTwoPencils2014-07-26 08:11:59 +00:00Commented Jul 26, 2014 at 8:11
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111. All arrays are objects. 2. Arrays of floats are not arrays of objects (so your "corrected" code will not compile)Stack Exchange Broke The Law– Stack Exchange Broke The Law2014-07-26 08:13:36 +00:00Commented Jul 26, 2014 at 8:13
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4How is this not a duplicate 6 years after Stack Overflow launched?Peter Mortensen– Peter Mortensen2014-07-26 19:33:17 +00:00Commented Jul 26, 2014 at 19:33
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2 Answers
Arrays are objects in Java. So an array of floats is an object.
BTW, Object o = new Object[20]; is also valid, since an array of objects is an object.
Also note that Object[] oa = new float[20]; is invalid, since primitive floats are not objects, and an array of floats is thus not an array of objects. What would be correct is
Object[] oa = new Float[20];
Regarding arrays, since they are objects, they have all the methods of java.lang.Object. They also have a public final attribute length, and they are Cloneable and Serializable:
Object o = new float[20];
System.out.println("o instanceof Serializable = " + (o instanceof Serializable)); // true
System.out.println("o instanceof Cloneable = " + (o instanceof Cloneable)); // true
10 Comments
Rajesh Kumar
Is there any replacement to "Object" in the statement "Object oa = new float[20];"? I understood your answer, but I am trying to mingle the line "Arrays are objects in java"
Drathier
No, there isn't anything as generic as Object when it comes to primitives such as int, float, void, char...
JB Nizet
Yes, there is. A float[] is of type float[], but also Object, Serializable and Cloneable.
Rajesh Kumar
@Chief Two Pencils: Thanks, now I understood from your comment that "float[]" is replacement for "Object" and it solved my doubt
ChiefTwoPencils
@RajeshKumar, glad it helped but I was kinda just proving a point. JB's is better in regards to your question.
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Basically, Object is a super class for all the objects in Java. So, making a reference of Object class and then using it as any other object is valid.
Object ob = new Integer(5);
Arrays in Java are nothing but the objects, so reference of Object class can be assigned an array.
