Vector v = new Vector();
i<10;
v.add(new Integer(i));// what does this lien do?
I dont understand, what does calling (new Integer()) do? Is is calling the constructor
and passing the value i in it.
Why can't we just pass the value i directly and add it in the vector.
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Integerclass is a wrapper class for anint. While anintis a primitive (has no methods, etc.), anIntegeris a class (does have objects).The constructor for an Integer class requires an int, which is why you see the constructor call new Integer(i). Vectors …
cos the add method of the vector only accepts objects. therefore, primitive values like ints will not be accepted. only Integer objects will be accepted. refer api:
http://download.oracle.com/javase/1.4.2/docs/api/java/util/Vector.html
The Integer class is a wrapper class for an int . While an int is a primitive (has no methods, etc.), an Integer is a class (does have objects).
The constructor for an Integer class requires an int, which is why you see the constructor call new Integer(i). Vectors require Integers, therefore you need to make the int into an Integer.
Thank you all for your replies.
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