MCQOPTIONS
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MCQOPTIONS
This section includes 133 Mcqs, each offering curated multiple-choice questions to sharpen your Javascript knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
How many properties are there in the interface PerformanceTiming?$? |
| A. | 21 |
| B. | 22 |
| C. | 23 |
| D. | 24 |
| Answer» B. 22 | |
| 102. |
What can be done to monitor the memory usage?$? |
| A. | Profiling |
| B. | Sequencing |
| C. | Serializing |
| D. | None of the mentioned |
| Answer» B. Sequencing | |
| 103. |
What does the rendering engine do when it encounters JavaScript?$? |
| A. | Skips the code |
| B. | Continues painting |
| C. | Switches to Javascript Interpreter |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 104. |
Which of the following is a read-only property?$? |
| A. | PerformanceTiming.navigationStart |
| B. | PerformanceTiming.fetchStart |
| C. | PerformanceTiming.navigationStart & PerformanceTiming.fetchStart |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 105. |
What is the function of the memory object?$? |
| A. | Gets unused memory details |
| B. | Shows optimization |
| C. | Gets memory usage |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 106. |
What does the constant TYPE_BACK_FORWRD indicate?$? |
| A. | Navigation via browser history |
| B. | Navigation via user request |
| C. | Navigation via URL |
| D. | None of the mentioned |
| Answer» B. Navigation via user request | |
| 107. |
What are the parameters of the attachEvent function?$? |
| A. | Function |
| B. | Function, Event |
| C. | Event, Function |
| D. | Event |
| Answer» D. Event | |
| 108. |
Which of the following property is associated with the Response event?$? |
| A. | responseStart |
| B. | responseEnd |
| C. | both responseStart and responseEnd |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 109. |
What will happen if the browser encounters a script tag without an src attribute?$? |
| A. | Throws an error |
| B. | Throws an exception |
| C. | Sends it to the compiler |
| D. | Sends it to the interpreter |
| Answer» E. | |
| 110. |
Which of the below does not belong to the Render Engine work flow?$? |
| A. | Paint DOM elements |
| B. | Parse Content |
| C. | uild DOM nodes in render tree |
| D. | None of the mentioned |
| Answer» E. | |
| 111. |
What is the default value of the asyc attribute?$? |
| A. | 0 |
| B. | 1 |
| C. | False |
| D. | True |
| Answer» E. | |
| 112. |
Which of the following are client-side JavaScript object?$? |
| A. | Database |
| B. | Cursor |
| C. | Client |
| D. | FileUpLoad |
| Answer» E. | |
| 113. |
Why do we need to use an onload event in the script tag after using the async attribute?$? |
| A. | Invoke code during page loading |
| B. | Invoke code during script loading |
| C. | Invoke code during downloading |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 114. |
What will happen if the browser encounters a script tag without an src attribute?? |
| A. | Throws an error |
| B. | Throws an exception |
| C. | Sends it to the compiler |
| D. | Sends it to the interpreter |
| Answer» E. | |
| 115. |
Why do we need to use an onload event in the script tag after using the async attribute?? |
| A. | Invoke code during page loading |
| B. | Invoke code during script loading |
| C. | Invoke code during downloading |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 116. |
Which of the below does not belong to the Render Engine work flow?? |
| A. | Paint DOM elements |
| B. | Parse Content |
| C. | uild DOM nodes in render tree |
| D. | None of the mentioned |
| Answer» E. | |
| 117. |
What is the default value of the asyc attribute?? |
| A. | 0 |
| B. | 1 |
| C. | False |
| D. | True |
| Answer» E. | |
| 118. |
Which of the following are client-side JavaScript object?? |
| A. | Database |
| B. | Cursor |
| C. | Client |
| D. | FileUpLoad |
| Answer» E. | |
| 119. |
What is the purpose of holding whatever tag you create in the attribute type? |
| A. | To have more information |
| B. | To identify the scripting language |
| C. | All of the mentioned |
| D. | None of the mentioned |
| Answer» C. All of the mentioned | |
| 120. |
Which of the following does JSON.stringify not serialize? |
| A. | Undefined values |
| B. | Functions within an object |
| C. | Both Undefined values and Functions within an object |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 121. |
Which of the following does not serialize the undefined values or objects within an object? |
| A. | JSON.string |
| B. | JSON |
| C. | JSON.stringify |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 122. |
What does the method Performance.now() return? |
| A. | DOMTimeStamp |
| B. | DOMHighResTimeStamp |
| C. | DOMStamp |
| D. | TimeStamp |
| Answer» C. DOMStamp | |
| 123. |
What is the purpose of the constant TYPE_RELOAD? |
| A. | Reload performed |
| B. | Reload not performed |
| C. | Reload must be performed |
| D. | None of the mentioned |
| Answer» B. Reload not performed | |
| 124. |
What is the purpose of the timing property in the window.performance object? |
| A. | Time of navigation event |
| B. | Time of page load event |
| C. | Time of navigation and page load event |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 125. |
What is the purpose of using the async attribute in the script tag? |
| A. | Load the script asynchronously |
| B. | Load the script synchronously |
| C. | Load the page asynchronously |
| D. | Load the page synchronously |
| Answer» B. Load the script synchronously | |
| 126. |
What is the purpose of the method createDocumentFragment()? |
| A. | Creates a fragment object |
| B. | Creates a document fragment |
| C. | Creates imaginary node object |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 127. |
What is the inital step to set up a CSS Lazy Loading? |
| A. | Fetching data |
| B. | Loading the script |
| C. | Loading the page |
| D. | Adding the event listener |
| Answer» B. Loading the script | |
| 128. |
What is the purpose of the property PerformanceTiming.navigationStart? |
| A. | Ready to end the navigation |
| B. | Ready to jump the navigation |
| C. | Ready for navigation |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 129. |
How many properties does a prototype object have? |
| A. | 6 |
| B. | 7 |
| C. | 8 |
| D. | 9 |
| Answer» C. 8 | |
| 130. |
What does the usedJsHeapSize property indicate? |
| A. | Amount of memory used |
| B. | Amount of memory unused |
| C. | Amount of memory used & unused |
| D. | None of the mentioned |
| Answer» B. Amount of memory unused | |
| 131. |
What does it indicate when the type attribute of the navigation object is set to 2? |
| A. | Navigation by moving back through history |
| B. | Navigation by moving forward through history |
| C. | Navigation by moving back & forward through history |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 132. |
How many properties are available in a memory object? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 133. |
Which of the following property gives access to the JavaScript memory usage data? |
| A. | performance.memory |
| B. | memory(performance) |
| C. | performance(memory) |
| D. | none of the mentioned |
| Answer» B. memory(performance) | |