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MCQOPTIONS
This section includes 302 Mcqs, each offering curated multiple-choice questions to sharpen your Javascript knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Consider the following code snippetfunction tail(o){for (; o.next; o = o.next) ;return o;}Will the above code snippet work? If not, what will be the error? |
| A. | o, this will throw an exception as only numerics can be used in a for loop |
| B. | o, this will not iterate |
| C. | es, this will work |
| D. | o, this will result in a runtime error with the message “Cannot use Linked List” |
| Answer» D. o, this will result in a runtime error with the message “Cannot use Linked List” | |
| 2. |
Consider the following code snippetfunction printArray(a){var len = a.length, i = 0;if (len == 0)console.log("Empty Array");else{do{console.log(a[i]);} while (++i < len);}}What does the above code result? |
| A. | rints the numbers in the array in order |
| B. | rints the numbers in the array in the reverse order |
| C. | rints 0 to the length of the array |
| D. | rints “Empty Array” |
| Answer» B. rints the numbers in the array in the reverse order | |
| 3. |
Consider the following statementsvar count = 0;while (count < 10){.log(count);count++;}In the above code snippet, what happens? |
| A. | he values of count is logged or stored in a particular location or storage |
| B. | he value of count from 0 to 9 is displayed in the console |
| C. | n error is displayed |
| D. | n exception is thrown |
| Answer» C. n error is displayed | |
| 4. |
“An expression that can legally appear on the left side of an assignment expression.” is a well known explanation for variables, properties of objects, and elements of arrays. They are called |
| A. | roperties |
| B. | rototypes |
| C. | value |
| D. | efinition |
| Answer» D. efinition | |
| 5. |
Which is a more efficient code snippet ?Code 1 :for(var=10;num>=1;num--){document.writeln(num);}Code 2 :var num=10;while(num>=1){document.writeln(num);num++;} |
| A. | ode 1 |
| B. | ode 2 |
| C. | oth Code 1 and Code 2 |
| D. | annot Compare |
| Answer» B. ode 2 | |
| 6. |
Consider the following statementsvar text = "testing: 1, 2, 3"; // Sample textvar pattern = /d+/g // Matches all instances of one or more digitsIn order to check if the pattern matches with the string “text”, the statement is |
| A. | ext==pattern |
| B. | ext.equals(pattern) |
| C. | ext.test(pattern) |
| D. | attern.test(text) |
| Answer» E. | |
| 7. |
Consider the following snippet codevar string1 = ”123”;var intvalue = 123;alert( string1 + intvalue )The result would be |
| A. | 23246 |
| B. | 46 |
| C. | 23123 |
| D. | xception |
| Answer» D. xception | |
| 8. |
Identify the process done in the below code snippeto = {x:1, y:{z:[false,null,"]}};s = JSON.(o);p = JSON.parse(s); |
| A. | bject Encapsulation |
| B. | bject Serialization |
| C. | bject Abstraction |
| D. | bject Encoding |
| Answer» C. bject Abstraction | |
| 9. |
Consider the below given syntaxbook[datatype]=assignment_value;In the above syntax, the datatype within the square brackets must be |
| A. | n integer |
| B. | String |
| C. | n object |
| D. | one of the mentioned |
| Answer» C. n object | |
| 10. |
Consider the following code snippet :var book = {"main title": "JavaScript",'sub-title': "The Definitive Guide","for": "all audiences",author: {firstname: "David",surname: "Flanagan"}};In the above snippet, firstname and surname are |
| A. | roperties |
| B. | roperty values |
| C. | roperty names |
| D. | bjects |
| Answer» D. bjects | |
| 11. |
Consider the following code snippetfunction f(o){if (o === undefined) debugger;}What could be the task of the statement debugger? |
| A. | t does nothing but a simple breakpoint |
| B. | t debugs the error in that statement and restarts the statement’s execution |
| C. | t is used as a keyword that debugs the entire program at once |
| D. | ll of the mentioned |
| Answer» B. t debugs the error in that statement and restarts the statement’s execution | |
| 12. |
Consider the following code snippetwhile (a != 0){if (spam>a == 1)continue;else++;}What will be the role of the continue keyword in the above code snippet? |
| A. | he continue keyword restarts the loop |
| B. | he continue keyword skips the next iteration |
| C. | he continue keyword skips the rest of the statements in that iteration |
| D. | one of the mentioned |
| Answer» D. one of the mentioned | |
| 13. |
Among the following, which one is a ternary operator? |
| A. | + |
| B. | : |
| C. | – |
| D. | ?: |
| Answer» E. | |
| 14. |
What kind of an expression is “new Point(2,3)”? |
| A. | Primary Expression |
| B. | Object Creation Expression |
| C. | Invocation Expression |
| D. | Constructor Calling Expression |
| Answer» C. Invocation Expression | |
| 15. |
JavaScript is a _______________ language |
| A. | Object-Oriented |
| B. | High-level |
| C. | Assembly-language |
| D. | Object-Based |
| Answer» E. | |
| 16. |
A conditional expression is also called a |
| A. | Alternate to if-else |
| B. | Immediate if |
| C. | If-then-else statement |
| D. | None of the mentioned |
| Answer» C. If-then-else statement | |
| 17. |
A statement block is a |
| A. | conditional block |
| B. | block that contains a single statement |
| C. | Both conditional block and single statement |
| D. | block that combines multiple statements into a single compound statement |
| Answer» E. | |
| 18. |
The “var” and “function” are |
| A. | Keywords |
| B. | Declaration statements |
| C. | Datatypes |
| D. | Prototypes |
| Answer» C. Datatypes | |
| 19. |
Consider the following statements switch(expression) { statements } In the above switch syntax, the expression is compared with the case labels using which of the following operator(s) ? |
| A. | |
| B. | equals |
| C. | equal |
| D. | |
| Answer» E. | |
| 20. |
Consider the following statements var count = 0; while (count < 10) { console.log(count); count++; } In the above code snippet, what happens? |
| A. | The values of count is logged or stored in a particular location or storage |
| B. | The value of count from 0 to 9 is displayed in the console |
| C. | An error is displayed |
| D. | An exception is thrown |
| Answer» C. An error is displayed | |
| 21. |
The enumeration order becomes implementation dependent and non-interoperable if : |
| A. | If the object inherits enumerable properties |
| B. | The object does not have the properties present in the integer array indices |
| C. | The delete keyword is never used |
| D. | Object.defineProperty() is not used |
| Answer» B. The object does not have the properties present in the integer array indices | |
| 22. |
Consider the following code snippet function printArray(a) { var len = a.length, i = 0; if (len == 0) console.log("Empty Array"); else { do { console.log(a[i]); } while (++i < len); } }What does the above code result? |
| A. | Prints the numbers in the array in order |
| B. | Prints the numbers in the array in the reverse order |
| C. | Prints 0 to the length of the array |
| D. | Prints “Empty Array” |
| Answer» B. Prints the numbers in the array in the reverse order | |
| 23. |
Consider the following code snippet function tail(o){ for (; o.next; o = o.next) ; return o; }Will the above code snippet work? If not, what will be the error? |
| A. | No, this will throw an exception as only numerics can be used in a for loop |
| B. | No, this will not iterate |
| C. | Yes, this will work |
| D. | No, this will result in a runtime error with the message “Cannot use Linked List” |
| Answer» D. No, this will result in a runtime error with the message “Cannot use Linked List” | |
| 24. |
One of the special feature of an interpreter in reference with the for loop is that |
| A. | Before each iteration, the interpreter evaluates the variable expression and assigns the name of the property |
| B. | The iterations can be infinite when an interpreter is used |
| C. | The body of the loop is executed only once |
| D. | All of the mentioned |
| Answer» B. The iterations can be infinite when an interpreter is used | |
| 25. |
What will happen if the body of a for/in loop deletes a property that has not yet been enumerated? |
| A. | The property will be stored in a cache |
| B. | The loop will not run |
| C. | That property will not be enumerated |
| D. | All of the mentioned |
| Answer» D. All of the mentioned | |
| 26. |
Consider the following code snippet while (a != 0) { if (a == 1) continue; else a++; } What will be the role of the continue keyword in the above code snippet? |
| A. | The continue keyword restarts the loop |
| B. | The continue keyword skips the next iteration |
| C. | The continue keyword skips the rest of the statements in that iteration |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 27. |
Local Browser used for validations on the Web Pages uses __________. |
| A. | Java |
| B. | HTML |
| C. | CSS |
| D. | JS |
| Answer» E. | |
| 28. |
JavaScript is also called as _____________. |
| A. | Server Side Scripting Language |
| B. | Browser Side Scripting Language |
| C. | Client Side Scripting Language |
| D. | Both B and C |
| Answer» E. | |
| 29. |
Why JavaScript is called as Lightweight Programming Language ? |
| A. | because JS is available free of cost |
| B. | because JS is client side scripting |
| C. | because we can add programming functionality inside JS |
| D. | because JS can provide programming functionality inside but up to certain extend. |
| Answer» E. | |
| 30. |
JavaScript Code is written inside file having extension __________. |
| A. | .jvs |
| B. | .javascript |
| C. | .js |
| D. | .jsc |
| Answer» D. .jsc | |
| 31. |
Cost for Using JavaScript in your HTML is _________ . |
| A. | Its Free !!! |
| B. | $10 / Year |
| C. | $15 / Year |
| D. | $5 / Year |
| Answer» B. $10 / Year | |
| 32. |
JavaScript is designed for following purpose - |
| A. | To Style HTML Pages |
| B. | To add interactivity to HTML Pages. |
| C. | To Perform Server Side Scripting Opertion |
| D. | To Execute Query Related to DB on Server |
| Answer» C. To Perform Server Side Scripting Opertion | |
| 33. |
Javascript is _________ language. |
| A. | Programming |
| B. | Application |
| C. | None of These |
| D. | Scripting |
| Answer» E. | |
| 34. |
What would be the output of the following fraction of code ? int Integer = 34 ; char String = 'S' ; System.out.print( Integer ) ; System.out.print( String ) ; |
| A. | Does not compile as Integer and String are API class names. |
| B. | 34 |
| C. | S |
| D. | 34 S |
| Answer» E. | |
| 35. |
What will be output of the following program code? public class Test{ public static void main(String[] a) { short x = 10; x = x*5; System.out.print(x); } } |
| A. | 50 |
| B. | 10 |
| C. | Compilation Error |
| D. | None of these |
| Answer» D. None of these | |
| 36. |
The following fraction of code double STATIC = 2.5 ; System.out.println( STATIC ); |
| A. | Prints 2.5 |
| B. | Rraises an error as STATIC is used as a variable which is a keyword |
| C. | Raises an exception |
| D. | None of these |
| Answer» B. Rraises an error as STATIC is used as a variable which is a keyword | |
| 37. |
A proper scripting language is a |
| A. | High level programming language |
| B. | Assembly level programming language |
| C. | Machine level programming language |
| D. | Low level programming language |
| Answer» B. Assembly level programming language | |
| 38. |
Which environment variable must the user enable in order to enable data tainting? |
| A. | ENABLE_TAINT |
| B. | MS_ENABLE_TAINT |
| C. | NS_ENABLE_TAINT |
| D. | ENABLE_TAINT_NS |
| Answer» D. ENABLE_TAINT_NS | |
| 39. |
Which tag can handle mouse events in Netscape? |
| A. | img |
| B. | a |
| C. | br |
| D. | none of the mentioned |
| Answer» B. a | |
| 40. |
What will the file_get_contents() return? |
| A. | Server’s response |
| B. | Errors |
| C. | Exception |
| D. | Client’s response |
| Answer» B. Errors | |
| 41. |
What is the purpose of the file_get_contents()? |
| A. | To get the errors and exceptions |
| B. | To get the client’s response |
| C. | To get the server’s response |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 42. |
What is the purpose of getting the paramerer fvonly? |
| A. | To repeat the view test |
| B. | To get the first view |
| C. | To debug the code |
| D. | None of the mentioned |
| Answer» C. To debug the code | |
| 43. |
What will happen if you set the private flag as 1? |
| A. | Test will be run only by the administrator |
| B. | Test will not be run |
| C. | Test is public |
| D. | Test is not displayed in public |
| Answer» E. | |
| 44. |
What is the purpose of the method par()? |
| A. | Makes the text vertical |
| B. | Makes the text horizontal |
| C. | Makes the text diagonal |
| D. | None of the mentioned |
| Answer» C. Makes the text diagonal | |
| 45. |
What is the purpose of the method symbols in R? |
| A. | Draw symbols |
| B. | Draw other shapes |
| C. | Draw symbols and other shapes |
| D. | None of the mentioned |
| Answer» C. Draw symbols and other shapes | |
| 46. |
What is the purpose of the method plot()? |
| A. | Displays symbols |
| B. | Displays charts |
| C. | Displays symbols and charts |
| D. | None of the mentioned |
| Answer» C. Displays symbols and charts | |
| 47. |
Which function is used to create data frames? |
| A. | data.frames() |
| B. | frame.data() |
| C. | data.frame() |
| D. | frame(data) |
| Answer» D. frame(data) | |
| 48. |
Which of the following list contains multiple data types? |
| A. | Vectors |
| B. | Data frames |
| C. | Matrices |
| D. | None of the mentioned |
| Answer» C. Matrices | |
| 49. |
Which is the function used to add the vectors? |
| A. | c() |
| B. | add(vectors) |
| C. | c(vectors) |
| D. | vectors.add |
| Answer» B. add(vectors) | |
| 50. |
Which of the following is the assignment operator? |
| A. | <- |
| B. | -> |
| C. | = |
| D. | |
| Answer» B. -> | |