A Review Of Guaranteed JavaScript-Developer-I Test Question

NEW QUESTION 1
Refer to the code below:
new Promise((resolve, reject) => { const fraction = Math.random();
if( fraction >0.5) reject("fraction > 0.5, " + fraction); resolve(fraction);
})
.then(() =>console.log("resolved"))
.catch((error) => console.error(error))
.finally(() => console.log(" when am I called?"));

When does Promise.finally on line 08 get called?

• A. When rejected
• B. When resolved and settled
• C. WHen resolved
• D. When resolved or rejected

Answer: D

NEW QUESTION 2
Refer to the code below:

What value can a developer expect when referencing o.js.secondCity?

• A. Undefined
• B. ‘ new york ’
• C. ‘ New York ’
• D. An error

Answer: B

NEW QUESTION 3
A developer is asked to fix some bugs reported by users. Todo that, the developer adds a breakpoint for debugging.
Function Car (maxSpeed, color){ This.maxspeed =masSpeed; This.color = color;
Let carSpeed = document.getElementById(‘ CarSpeed’); Debugger;
Let fourWheels =new Car (carSpeed.value, ‘red’);
When the code execution stops at the breakpoint on line 06, which two types of information are available in the browser console ?
Choose 2 answers:

• A. The values of the carSpeed and fourWheels variables
• B. A variable displaying the number of instances created for theCar Object.
• C. The style, event listeners and other attributes applied to the carSpeed DOM element
• D. The information stored in the window.localStorage property

Answer: CD

NEW QUESTION 4
Refer to the code snippet:

A developer writes this code to return a message to userattempting to register a new username. If the username is available, variable.
What is the return value of msg hen getAvailabilityMessage (“newUserName” ) is executed and getAvailability(“newUserName”) returns false?

• A. “Username available”
• B. “newUserName”
• C. “Msg is not defined”
• D. undefined

Answer: D

NEW QUESTION 5
Refer to the code:

Given the requirement to refactor the code above to JavaScript class format, which class definition is correct?
A)

B)

C)

D)

• A.

Answer: B

NEW QUESTION 6
A developer creates a simple webpage with an input field. When a user enters text in the input field and clicks the button, the actual value of the field must be displayed in the console.
Here is the HTML file content:

The developer wrote the javascript code below:

When the user clicks the button, the output is always “Hello”. What needs to be done to make this code work as expected?

• A. Replace line 04 with console.log(input .value);
• B. Replace line 03 with const input = document.getElementByName(‘input’);
• C. Replace line 02 with button.addCallback(“click”, function() {
• D. Replace line 02 withbutton.addEventListener(“onclick”, function() {

Answer: A

NEW QUESTION 7
A developer wants to create an object from a function in the browser using the code below:
Function Monster() { this.name =‘hello’ }; Const z = Monster();
What happens due to lack of the new keyword on line 02?

• A. The z variable is assigned the correct object.
• B. The z variable is assigned the correct object but this.name remains undefined.
• C. Window.name is assigned to ‘hello’ and the variable z remains undefined.
• D. Window.m is assigned the correct object.

Answer: C

NEW QUESTION 8
Refer to the code below:

What is the output of this function when called with an empty array?

• A. Returns 0
• B. Throws an error
• C. Returns 10
• D. Returns NaN

Answer: C

NEW QUESTION 9
Refer to the code snippet below:
Let array = [1, 2, 3, 4,4, 5, 4, 4];
For (let i =0; i < array.length; i++){ if (array[i] === 4) {
array.splice(i, 1);
}
}

What is the value of the array after the code executes?

• A. [1, 2, 3, 4, 5, 4, 4]
• B. [1, 2, 3, 4, 4, 5, 4]
• C. [1, 2, 3, 4, 5, 4]
• D. [1, 2, 3, 5]

Answer: C

NEW QUESTION 10
A developer wrote the following code: 01 let X = object.value;
02
3 try {
4 handleObjectValue(X); 05 } catch (error) {
6 handleError(error);
7 }
The developer has a getNextValue function to execute after handleObjectValue(), but does not want to execute getNextValue() if an error occurs.
How can the developer change the code to ensure thisbehavior?

• A. 03 try{4 handleObjectValue(x);5 } catch(error){6 handleError(error); 07 } then {8 getNextValue();9 }
• B. 03 try{4 handleObjectValue(x);5 } catch(error){6 handleError(error); 07 } finally {08 getNextValue();10 }
• C. 03 try{04handleObjectValue(x); 05 } catch(error){6 handleError(error);7 }8 getNextValue();
• D. 03 try {04 handleObjectValue(x)05 ……………………

Answer: D

NEW QUESTION 11
Refer to the code below: Let str = ‘javascript’; Str[0] = ‘J’;
Str[4] = ’S’;
After changing the string index values, the value of str is ‘javascript’. What is the reason for this value:

• A. Non-primitive values are mutable.
• B. Non-primitive values are immutable.
• C. Primitive values are mutable.
• D. Primitive values are immutable.

Answer: D

NEW QUESTION 12
A developer is setting up a new Node.js server with a client library that is built using events and callbacks. The library:
* Will establish aweb socket connection and handle receipt of messages to the server
* Will be imported with require, and made available with a variable called we.
The developer also wants to add error logging if a connection fails.
Given this info, which code segment shows the correct way to set up a client with two events that listen at execution time?

• A.
• B.
• C.
• D.

Answer: C

NEW QUESTION 13
A developer writers the code below to calculate the factorial of a given number.

What isthe result of executing line 04?

• A. 6
• B. -Infinity
• C. RuntimeError

Answer: D

Explanation:

NEW QUESTION 14
A developer has a formatName function that takes two arguments, firstName and lastName and returns a string. They want to schedule the
function to run once after five seconds.
What is the correct syntax to schedule this function?

• A. setTimeout (formatName(), 5000, "John", "BDoe");
• B. setTimeout (formatName('John', ‘'Doe'), 5000);
• C. setTimout(() => { formatName("John', 'Doe') }, 5000);
• D. setTimeout ('formatName', 5000, 'John", "Doe');

Answer: D

NEW QUESTION 15
Refer to the code below:
Let foodMenu1 =[‘pizza’, ‘burger’, ‘French fries’]; Let finalMenu = foodMenu1; finalMenu.push(‘Garlic bread’);
What is the value of foodMenu1 after the code executes?

• A. [ ‘pizza’,’Burger’, ‘French fires’, ‘Garlic bread’]
• B. [ ‘pizza’,’Burger’, ‘French fires’]
• C. [ ‘Garlic bread’ , ‘pizza’,’Burger’, ‘French fires’ ]
• D. [ ‘Garlic bread’]

Answer: B

NEW QUESTION 16
Refer to following code block:
Let array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,];
Let output =0;
For (let num of array){ if (output >0){
Break;
}
if(num % 2 == 0){
Continue;
}
Output +=num;
What is the value of output after the code executes?

• A. 16
• B. 36
• C. 11
• D. 25

Answer: A

NEW QUESTION 17
Given the code below: Function myFunction(){ A =5;
Var b =1;
}
myFunction(); console.log(a); console.log(b);
What is the expected output?

• A. Both lines 08 and 09 are executed, and the variables are outputted.
• B. Line 08outputs the variable, but line 09 throws an error.
• C. Line 08 thrones an error, therefore line 09 is never executed.
• D. Both lines 08 and 09 are executed, but values outputted are undefined.

Answer: B

NEW QUESTION 18
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