JAVA英文笔试题

JAVA英文笔试题

1.what is oracle.
　　2.what is major differenece oracle8i and oracle9i.
　　4.tell me some thing ur self.
　　5.please tell me about oops.
　　6.what is single inheritance.
　　7.what is multiple inheritance.
　　8.can java support multiple inheritance.
　　9.what is interface.
　　10.what is differenec between abstract class and interface.
　　11.how to u prove that abstrace class cannot instantiate directly.
　　12.what is differenece between string and stringbuffer.
　　13.what is immutable
　　14.how to write a program using sort program.
　　15 how to write a program using unsort program.
　　16.what is legacy.
　　17.what is legacy api
　　18.what is legacy interface.
　　19.what is main difference hashmap and hastable
　　20.what is main difference between arraylist and vector.
1. Oracle is an RDBMS product with DDL and DML from a company called Oracle Inc.
　　2. Difference between 8i and 9i is given in the Oracle site
　　3. Question not available
　　4. Something
　　5. oops is Object Oriented Programming
　　6.what is single inheritance.
　　ans:one class is inherited by only other one class
　　7.what is multiple inheritance.
　　ans:One class inheriting more than one class at atime
　　8.can java support multiple inheritance.
　　ans:No
　　9.what is interface.
　　ans:Interface has only method declarations but no defn
　　10.what is differenec between abstract class and interface.
　　ans:In abstract class some methods may contain definition,but in interface every method should be abstract
　　11.how to u prove that abstrace class cannot instantiate directly.
　　ans:As they dont have constructor they cant be instantiated
　　12.what is differenece between string and stringbuffer.
　　ans:Strings are immutable where as string buffer can be modified
　　13.what is immutable
　　ans:Which cant be changed
　　14.how to write a program using sort program.
　　15 how to write a program using unsort program.
　　ans: Both can be done using javascript
　　This is for Sort
　　function SelectTextSort(obj) { // sort by text
　　var N=obj.options.length;
　　for (var i=0;i<>
　　for (var j=i+1;j<>
　　if ( obj.options[i].text > obj.options[j].text ) {
　　var i1= (obj.options[i].selected == true ) ? true : false
　　var j1= (obj.options[j].selected == true ) ? true : false
　　var q1 = obj.options[j].text;
　　var q2 = obj.options[j].value;
　　obj.options[j].text = obj.options[i].text;
　　obj.options[j].value = obj.options[i].value;
　　obj.options[i].text = q1;
　　obj.options[i].value = q2;
　　obj.options[i].selected = (j1 && true ) ? true : false
　　obj.options[j].selected = (i1 && true ) ? true : false
　　}
　　}
　　}
　　return true
　　}
　　16.what is legacy.
　　17.what is legacy api
　　18.what is legacy interface.
　　ans: legacy is something that is old in terms of technology/ system
　　19.what is main difference hashmap and hastable
　　ans:Hash table is synchronised
　　20.what is main difference between arraylist and vector.
　　ans:Vector is synchronised