Java Programming Fundamentals

This is incorrect.

This is the correct answer. The first two characters from s1 and s2 (a vs a) are compared, they are equal. Then (b vs b) are compared they are also equal. Now ( c vs g ) are compared. Since, c is 4 less than g, so -4 is returned.

The correct answer is 16. When stringbuffer object is created the default capacity of the object is always 16. If the number of characters in the string increases the capacity will increase with the following formula-
2 * (previous capacity + 1). In this case hello has 5 characters, so default capacity will not change.

This is the correct answer, delete(int start , int end) deletes the characters from the start index till end-1 index. So, the welcome to java will delete the characters from 8 to 11 characters. So the resulting string remains “ Welcome ava”. Index starts from 0. Hence, this is the correct answer.

Yes, it is correct answer.

This is the correct answer.

Both char and string can be passed as the first parameter to the lastIndexOf() method. So, this is the correct answer.

This is wrong. Length() function returns the number of characters in the string. As we can count that the number of characters in the given string are 15. So, length() will return 15 not 14. charAt() function returns the character at the given index in the parameter. Remember that the index count starts at 0. So, charAt(0) is W, counting in this way we reach charAt(9) is o not T.  Hence, this is the correct answer.

This is wrong. Substring method takes two parameters (beginIndex,EndIndex).Substring( int Begin , int End). It returns the string from begin to end – 1. But, if the begin index is equal to the end index then an empty String with length 0 will be returned. So, here substring(4,4) will return an empty string of length 0. Hence, this is the correct answer.

There is no function defined in Scanner class to take character input. So, there is no function named nextChar(), hence this is the correct answer.

So, this option is correct.

IOException is not a subclass of RuntimeException class, this class is a Subclass of Exception class. This exception is thrown when invalid input/output are given. So, this is the correct answer, as this is not a subclass of RuntimeException class.

All of the given event types are valid in java. So, this option is the correct answer.

lastIndexOf(String s , index i) method return the last occurrence of string s before the from index. Return -1 if string not found. So, here the string to find is “Java” before the index 5, which means before the character m. But, string “java” is not present before the index 5, i.e. character m. So, it will return -1.

This is correct answer because all of the given layout managers are present in java awt.

There are 8 primitive data types in java. These are:-ByteShortIntLongDoubleCharFloatBoolean. So, this is correct answer.

This is the correct answer because there are  three constructors. 

This function is not defined in the Frame class. This function is defined in JFrame class in Swings. So, this method cannot be invoked using the object of Frame class. But, can be invoked using the Object of JFrame class. This method specifies the operation when the frame is closed. Hence, this would be false. Frame f1 = new frame();f1.setDefaultCloseOperation(int); so this is the correct answer.

This is correct answer because all of  given methods are valid in java event handling.

If a class implements an interface then it is necessary for that class to define body to all the methods defined in the interface, it is implementing. But, windowMoved() method is not present in windowListener interface. So, when a class will implement this interface this method need not to be define in the class. So, this option is correct.

This is correct answer because there are two constructors of borderlayout are present in Java. These are-BorderLayout()- creates a default borderlayout. BorderLayout(int hgap, int vgap)- creates a borderlayout with specified horizontal and vertical gap between the components. So, this answer is correct.

This is the correct answer because colour constructor creates a new colour, but it takes parameters in the range 0-255. But, here the value passed is 284(in first parameter). So, a runtime exception named “IllegalArgumentException” will be thrown by the JVM. Hence, this is the correct answer.

This is correct The constructor of the Font class takes three parameters :- First parameter is of String type, which specifies the name of the Font. Second parameter is of type int, which specifies the style of the font like Font.BOLD. Third parameter is of type int, which specifies the size of the font. Example, Font f1 = new Font(“Serif”, Font.BOLD, 32); So this option is true.

This is false choice because JList does not generate an ActionEvent. When we click an item in JList ListSelectionEvent is generated. So, this is the true  according to the question.

This option is correct because there is no method defined fillCircle() in Graphics class. So, this option is correct.