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Answers: Certified Java Programmer Mock Exam
No.AnswerRemark
1e  Compile-time error  There are two versions of the Math.round method. One accepts an argument of type float; the return type is int. The other accepts an argument of type double; the return type is long. A compile-time error is generated here due to the attempt to assign the long return value to the int variable, i2.  
2d  Prints: 1,2  The Math.round method returns the floor of the argument value plus 0.5. If the argument is of type float, then the return type is int. If the argument is of type double, then the return type is long.  
3c  Prints: 0  If NaN is the argument passed to Math.round, then the return value is zero. If the argument type is float, then the return type is int. If the argument type is double, then the return type is long.  
4d  Prints: 1.0,2.0  The Math.ceil method name is not overloaded. The Math.ceil method accepts an argument of type double and returns a double. The returned value is the smallest whole number that is greater than or equal to the argument.  
5a  Prints: 0.0,1.0  The Math.floor method name is not overloaded. The Math.floor method accepts an argument of type double and returns a double. The returned value is the largest whole number that is smaller than or equal to the argument.  
6a  Prints: 10.0  The Math class declares four versions of the abs method; each declares a pair of parameters of the same type. The parameter pair can be of type int, long, float or double. The return type is the same as the argument types. At run-time, the arguments might not match the declared parameter types; so one argument or both might require an implicit conversion to an acceptable type. If both arguments are of type byte, short or char, then both will be promoted to type int. If only one argument is of type byte, short or char, then it will be promoted to the type of the other argument. If both arguments are of type int, long, float or double but the types differ, then a primitive widening conversion will be applied to one of the two arguments.  
7b  Compile-time error at 1  At line 1, the invocation of the Math.min method produces a return value of type int. The variable b1 is of type short; so the assignment expression results in a compile-time error. The Math class declares four versions of the min method; each declares a pair of parameters of the same type. The parameter pair can be of type int, long, float or double. The return type is the same as the argument types. At run-time, the arguments might not match the declared parameter types; so one argument or both might require an implicit conversion to an acceptable type. If both arguments are of type byte, short or char, then both will be promoted to type int. If only one argument is of type byte, short or char, then it will be promoted to the type of the other argument. If both arguments are of type int, long, float or double but the types differ, then a primitive widening conversion will be applied to one of the two arguments.  
8b  Compile-time error at 1  At line 1, the invocation of the Math.min method produces a return value of type int. The variable a1 is of type byte; so the assignment expression results in a compile-time error. The Math class declares four versions of the min method; each declares a pair of parameters of the same type. The parameter pair can be of type int, long, float or double. The return type is the same as the argument types. At run-time, the arguments might not match the declared parameter types; so one argument or both might require an implicit conversion to an acceptable type. If both arguments are of type byte, short or char, then both will be promoted to type int. If only one argument is of type byte, short or char, then it will be promoted to the type of the other argument. If both arguments are of type int, long, float or double but the types differ, then a primitive widening conversion will be applied to one of the two arguments.  
9c  Prints: int,int,int  The Math class declares four versions of the min method; each declares a pair of parameters of the same type. The parameter pair can be of type int, long, float or double. The return type is the same as the argument types. At run-time, the arguments might not match the declared parameter types; so one argument or both might require an implicit conversion to an acceptable type. If both arguments are of type byte, short or char, then both will be promoted to type int. If only one argument is of type byte, short or char, then it will be promoted to the type of the other argument. If both arguments are of type int, long, float or double but the types differ, then a primitive widening conversion will be applied to one of the two arguments.  
10d  Prints: int,int,long  The Math class declares four versions of the min method; each declares a pair of parameters of the same type. The parameter pair can be of type int, long, float or double. The return type is the same as the argument types. At run-time, the arguments might not match the declared parameter types; so one argument or both might require an implicit conversion to an acceptable type. If both arguments are of type byte, short or char, then both will be promoted to type int. If only one argument is of type byte, short or char, then it will be promoted to the type of the other argument. If both arguments are of type int, long, float or double but the types differ, then a primitive widening conversion will be applied to one of the two arguments.  
11c  Prints: long,float,double  The Math class declares four versions of the min method; each declares a pair of parameters of the same type. The parameter pair can be of type int, long, float or double. The return type is the same as the argument types. At run-time, the arguments might not match the declared parameter types; so one argument or both might require an implicit conversion to an acceptable type. If both arguments are of type byte, short or char, then both will be promoted to type int. If only one argument is of type byte, short or char, then it will be promoted to the type of the other argument. If both arguments are of type int, long, float or double but the types differ, then a primitive widening conversion will be applied to one of the two arguments.  
12d  Prints: double  The Math.random method returns a value of type double. The range of values is greater than or equal to zero and less than one.  
13e  Compile-time error  The Math.random method does not accept a seed value. If your application requires a seed, then use java.util.Random.  
14d  Prints: double,double,double  The Math.sin, Math.cos and Math.tan methods return a value of type double.  
15a  g  h  i  b1  b7  b8  b9  The Math.random method returns a value that is equal to or greater than zero and less than 1.0.  
16l  None of the above  All methods of the java.lang.Math class are static.  
17a  d  e  abs  max  min   
18f  Prints: DDDLDD  The round method does not return either of the two floating point primitive types, float or double. The ceil, sin and sqrt methods return only a value of type double. The abs and max methods are able to return an int, long, float or double depending on the argument type.  
19e  Prints: DDDD  The floor and ceil methods are not overloaded. There is only one version of each method. The parameter type is double, and the return type is double.  
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