OCP Oracle Certified Professional Java SE 11 Developer Practice Tests. Jeanne Boyarsky

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Chapter 1 Working with Java Data Types

       THE OCP EXAM TOPICS COVERED IN THIS PRACTICE TEST INCLUDE THE FOLLOWING:

      1 Which of the following are not valid variable names? (Choose two.)__blue2blueblue$Blue

      2 What is the value of tip after executing the following code snippet?int meal = 5; int tip = 2; var total = meal + (meal>6 ? tip++ : tip--);1237None of the above

      3 Which is equivalent to var q = 4.0f;?float q = 4.0f;Float q = 4.0f;double q = 4.0f;Double q = 4.0f;Object q = 4.0f;

      4 What is the output of the following?12: var b = "12"; 13: b += "3"; 14: b.reverse(); 15: System.out.println(b.toString());12123321The code does not compile.

      5 What is the output of the following?5: var line = new StringBuilder("-"); 6: var anotherLine = line.append("-"); 7: System.out.print(line == anotherLine); 8: System.out.print(" "); 9: System.out.print(line.length());false 1false 2true 1true 2It does not compile.

      6 Given the following Venn diagram and the boolean variables, apples, oranges, and bananas, which expression most closely represents the filled‐in region of the diagram?apples && oranges && !bananasorange || (oranges && !bananas)(apples || bananas) && orangesoranges && apples(apples || oranges) && !bananasapples ^ oranges

      7 What is the output of the following?5: var line = new String("-"); 6: var anotherLine = line.concat("-"); 7: System.out.print(line == anotherLine); 8: System.out.print(" "); 9: System.out.print(line.length());false 1false 2true 1true 2Does not compile

      8 Which can fill in the blank? (Choose two.)public void math() { _____ pi = 3.14; }bytedoublefloatshortvar

      9 Fill in the blanks: The operators !=, _______, _______, _______, and ++ are listed in the same or increasing level of operator precedence. (Choose two.)==, *, !/, %, **, ‐‐, /!, *, %+=, &&, **, <, /

      10 How many of these compile?18: Comparator<String> c1 = (j, k) -> 0; 19: Comparator<String> c2 = (String j, String k) -> 0; 20: Comparator<String> c3 = (var j, String k) -> 0; 21: Comparator<String> c4 = (var j, k) -> 0; 22: Comparator<String> c5 = (var j, var k) -> 0;012345

      11 The author of this method forgot to include the data type. Which of the following reference types can best fill in the blank to complete this method?public static void secret(___________ mystery) { char ch = mystery.charAt(3); mystery = mystery.insert(1, "more"); int num = mystery.length(); }StringStringBuilderBothNeither

      12 What is the output of the following?var teams = new StringBuilder("333"); teams.append(" 806"); teams.append(" 1601"); System.out.print(teams);333333 806 1601The code compiles but outputs something else.The code does not compile.

      13 Which of the following declarations does not compile?double num1, int num2 = 0;int num1, num2;int num1, num2 = 0;int num1 = 0, num2 = 0;All of the aboveNone of the above

      14 Given the file Magnet.java shown, which of the marked lines can you independently insert the line var color; into and still have the code compile?// line a1 public class Magnet { // line a2 public void attach() { // line a3 } // line a4 }a2a3a2 and a3a1, a2, a3, and a4None of the above

      15 Which is one of the lines output by this code?10: var list = new ArrayList<Integer>(); 11: list.add(10); 12: list.add(9); 13: list.add(8); 14: 15: var num = 9; 16: list.removeIf(x -> {int keep = num; return x != keep;}); 17: System.out.println(list); 18: 19: list.removeIf(x -> {int keep = num; return x == keep;}); 20: System.out.println(list);[][8, 10][8, 9, 10][10, 8]The code does not compile.

      16 Which of the following can fill in the blank so the code prints true?var happy = " :) - (: "; var really = happy.trim(); var question = _____________________; System.out.println(really.equals(question));happy.substring(0, happy.length() ‐ 1)happy.substring(0, happy.length())happy.substring(1, happy.length() ‐ 1)happy.substring(1, happy.length())

      17 How many of the following lines contain a compiler error?double num1 = 2.718; double num2 = 2._718; double num3 = 2.7_1_8; double num4 = _2.718;01234

      18 What is the output of the following application?public class Airplane { static int start = 2; final int end; public Airplane(int x) { x = 4; end = x; } public void fly(int distance) { System.out.print(end-start+" "); System.out.print(distance); } public static void main(String… start) { new Airplane(10).fly(5); } }2 58 56 5The code does not compile.None of the above.

      19 What is the output of the following class?1: package rocket; 2: public class Countdown { 3: public static void main(String[] args) { 4: var builder = "54321"; 5: builder = builder.substring(4); 6: System.out.println(builder.charAt(2)); 7: } 8: }234None of the above

      20 What is the output СКАЧАТЬ