最近更新された2026年01月テストエンジン練習テストはJavaScript-Developer-I試験問題解答！ [Q99-Q120]

質問 99
Refer to the following code:
function test (val) {
If (val === undefined) {
return ‘Undefined values!’ ;
}
if (val === null) {
return ‘Null value! ‘;
}
return val;
}
Let x;
test(x);
What is returned by the function call on line 13?

質問 100
Refer the following code

What is the value of array after code executes?

質問 101
Referto the following code:

Which two statement could be inserted at line 17 to enable the function call on line 18?
Choose 2 answers

質問 102
developer wants to use a module named universalContainersLib and them call functions from it.
How should a developer import every function from the module and then call the functions foo and bar ?

質問 103
Refer to the code below:
const event = new CustomEvent(
//Missing Code
);
obj.dispatchEvent(event);
A developer needs to dispatch a custom event called update to send information about recordId.
Which two options could a developer insert at the placeholder in line 02 to achieve this?
Choose 2 answers

質問 104
Refer to the code below?
Let searchString = ‘ look for this ‘;
Which two options remove the whitespace from the beginning of searchString?
Choose 2 answers

質問 105
A developer writes the code below to calculate the factorial of a given number function sum(number){ return number * sum(number-1);
}
sum(3);
what is the result of executing the code.

質問 106
Refer to following code:
class Vehicle {
constructor(plate) {
This.plate =plate;
}
}
Class Truck extends Vehicle {
constructor(plate, weight) {
//Missing code
This.weight = weight;
}
displayWeight() {
console.log(‘The truck ${this.plate} has a weight of ${this.weight} lb.’);}} Let myTruck = new Truck(‘123AB’, 5000); myTruck.displayWeight(); Which statement should be added to line 09 for the code to display ‘The truck 123AB has a weight of 5000lb.’?

質問 107
A developer needs to test this function:
01 const sum3 = (arr) => (
02 if (!arr.length) return 0,
03 if (arr.length === 1) return arr[0],
04 if (arr.length === 2) return arr[0] + arr[1],
05 return arr[0] + arr[1] + arr[2],
06 );
Which two assert statements are valid tests for the function?
Choose 2 answers

質問 108
Which two code snippets show working examples of a recursive function?
Choose 2 answers

質問 109
There is a new requirement for a developer to implement a currPrice method that will return the current price of the item or sales..

What is the output when executing the code above

質問 110
Given the JavaSript below:

Which code should replace the placeholder comment on line 05 to hide accounts that do not match the search string?

質問 111
Refer to the code below:
const event = new CustomEvent(
//Missing Code
);
obj.dispatchEvent(event);
A developer needs to dispatch a custom event called update to send information about recordId.
Which two options could a developer insert at the placeholder in line 02 to achieve this?
Choose 2 answers

質問 112
Refer to the following code:
Let sampletext = ‘The quick brown fox Jumps’;
A developer need to determine if a certain substring is part of a string.
Which three expressions return true for the give substring? Choose 3 answers

質問 113
Refer to the code below:
Function changeValue(obj) {
Obj.value = obj.value/2;
}
Const objA = (value: 10);
Const objB = objA;
changeValue(objB);
Const result = objA.value;
What is the value of result after the code executes?

質問 114
Cloud Kicks has a classto represent items for sale in an online store, as shown below:
Class Item{
constructor (name, price){
this.name = name;
this.price = price;
}
formattedPrice(){
return ‘s’ + String(this.price);}}
A new business requirement comes in that requests a ClothingItem class that should have all of the properties and methods of the Item class but will also have properties that are specific to clothes.
Which line of code properly declares the clothingItem class such that it inherits from Item?

質問 115
The developer wants to test the array shown:
Const arr = Array (5) . fill (0);
Which two test are the most accurate for this array? Choose 2 answers

質問 116
Which code statement correctly retrieves and returns an object from localStorage?

質問 117
Refer to following code:
class Vehicle {
constructor(plate) {
This.plate =plate;
}
}
Class Truck extends Vehicle {
constructor(plate, weight) {
//Missing code
This.weight = weight;
}
displayWeight() {
console.log(‘The truck ${this.plate} has a weight of ${this.weight} lb.’);}}
Let myTruck = new Truck(‘123AB’, 5000);
myTruck.displayWeight();
Which statement should be added to line 09 for the code to display ‘The truck 123AB has a
weight of 5000lb.’?

質問 118
Refer to the code below:
console.log(”start);
Promise.resolve(‘Success’) .then(function(value){
console.log(‘Success’);
});
console.log(‘End’);
What is the output after the code executes successfully?

質問 119
There is a new requirement for a developer to implement a currPrice method that will return the current price of the item or sales..

What is the output when executing the code above

質問 120
Refer to the code below:

Considering that JavaScript is single-threaded, what is the output of line 08 after the code executes?