Quiz 1 Solutions

Quiz 1 Solutions - incompatible data types, and will raise...

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Computer Science 302 Section 3 Quiz 1 Solutions 2006-09-15 Name: 1 (1 point) Which of the following blocks of code will cause a compile-time error? A int a = 1; int b = 2; double c = a/b; The expression double c = a/b; is valid Java code because the runtime will perform integer division, discarding any fractional remainder. In this case, the variable c will be given the value 0 . B String s1 = "Hello"; String s2 = "World"; s2 = s1; System.out.println(s2); Assigning the string referenced by s1 to the variable s2 will not cause an error; it will just cause s2 to point to the same string. This block of code will print the text Hello , and the other String object will eventually be reclaimed by the garbage collector. C double d1 = 5.0 / 2; double d2 = d1 + "42"; System.out.println(d2); This is the correct answer. Because Java is a strongly typed language, it will not automatically convert strings to numbers, even when the string is a valid numerical representation. The compiler will recognize that the second line is trying to add
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Unformatted text preview: incompatible data types, and will raise a compile-time error. 2 (2 point) Write a series of statements that creates a variable of the Beeper type, assigns to it a new Beeper object, then sends the object the message beep with the single argument 5. Writing a line of that created the object was worth one point; writing a line that called the beep method was worth another point. The following answer would have received both points: Beeper beeperVariable = new Beeper(); beeperVariable.beep(5); 3 (2 point) On the following chart, mark where Javas type-handling system belongs. 1 6-Dynamic Static Weak Strong x Java is a staticly-typed language because the type of every variable is declared and known at the time of compilation. It is a strongly-typed language because data types cannot be automatically converted to other types (e.g. the string to double conversion in Question 1). Correct placement on each axis was worth one point. 2...
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Quiz 1 Solutions - incompatible data types, and will raise...

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