Salesforce JavaScript Developer I Cert
Practice Exam 2025 Questions and
Answers
Which two syntax examples correctly initialize a value to the variable strLang?
A. let strLang = 'javascript';
B. const strLang = 'java' + 'script';
C. let strLang = javascript;
D. str strLang = 'javascript'; - ....ANSWER ...-ANSWER:
A. let strLang = 'javascript';
B. const strLang = 'java' + 'script';
Additional Info:
Note that C doesn't have a value that has single quotes around the word 'javascript' and
for D, 'str' is not a proper identifier
Which statement sorts the following number array so it is in ascending order? const arr =
[7, 3, 400, 10];
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 1
,A. arr.sort();
B. arr.sort((a, b) => a - b);
C. arr.sort((a, b) => a < b);
D. arr.sort((a, b) => b - a); - ....ANSWER ...-ANSWER:
B. arr.sort((a, b) => a - b);
Additional Info:
A. The sort() function sorts values as strings, which will sort this as [10, 3, 400, 7].
C. The compare function expects a positive, negative, or 0 to be returned.
D. The compare function will actually reverse the order of the numbers.
Which statement sorts the following string array so it is in descending order? const arr =
["Banana", "Orange", "Apple", "Mango"];
A. arr.sort();
B. arr.sort((a, b) => a - b);
C. arr.reverse();
D. arr.sort((a, b) => b - a); - ....ANSWER ...-ANSWER:
C. arr.reverse();
Additional Info:
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 2
,A. The sort() function sorts values as strings in ASCENDING order: ["Apple",
"Banana", "Mango", "Orange"];
B,D. Expect a number array.
What are the different data types used in JavaScript? - ....ANSWER ...-ANSWER:
There are 8 basic data types in JavaScript:
1. Number for numbers of any kind: integer or floating-point, integers are limited by
±((2^53)-1).
2. BigInt is for integer numbers of arbitrary length.
3. String for strings. A string may have zero or more characters, there's no separate
single-character type.
4. Boolean for true/false.
5. NULL for unknown values - a standalone type that has a single value null. Note,
typeof null returns "object" even though it is NOT and object.
6. Undefined for unassigned values - a standalone type that has a single value undefined.
7. Object for more complex data structures.
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 3
, 8. Symbol for unique identifiers.
Which collections of data are ordered by a key? - ....ANSWER ...-ANSWER:
Map and set objects.
What is the proper syntax for adding placeholders in template literals? -
....ANSWER ...-ANSWER:
Use a dollar sign followed by curly brackets:
${expression}.
Additional Info:
let name = "John";
// embed a variable
alert( `Hello, ${name}!` ); // Hello, John!
// embed an expression
alert( `the result is ${1 + 2}` ); // the result is 3
Note this only works if you use backticks, `, and not single(') or double(") quotes
otherwise the results will be shown as literal, ie: Hello, ${name}!
How do you instantiate a value as a BigInt?
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 4
Practice Exam 2025 Questions and
Answers
Which two syntax examples correctly initialize a value to the variable strLang?
A. let strLang = 'javascript';
B. const strLang = 'java' + 'script';
C. let strLang = javascript;
D. str strLang = 'javascript'; - ....ANSWER ...-ANSWER:
A. let strLang = 'javascript';
B. const strLang = 'java' + 'script';
Additional Info:
Note that C doesn't have a value that has single quotes around the word 'javascript' and
for D, 'str' is not a proper identifier
Which statement sorts the following number array so it is in ascending order? const arr =
[7, 3, 400, 10];
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 1
,A. arr.sort();
B. arr.sort((a, b) => a - b);
C. arr.sort((a, b) => a < b);
D. arr.sort((a, b) => b - a); - ....ANSWER ...-ANSWER:
B. arr.sort((a, b) => a - b);
Additional Info:
A. The sort() function sorts values as strings, which will sort this as [10, 3, 400, 7].
C. The compare function expects a positive, negative, or 0 to be returned.
D. The compare function will actually reverse the order of the numbers.
Which statement sorts the following string array so it is in descending order? const arr =
["Banana", "Orange", "Apple", "Mango"];
A. arr.sort();
B. arr.sort((a, b) => a - b);
C. arr.reverse();
D. arr.sort((a, b) => b - a); - ....ANSWER ...-ANSWER:
C. arr.reverse();
Additional Info:
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 2
,A. The sort() function sorts values as strings in ASCENDING order: ["Apple",
"Banana", "Mango", "Orange"];
B,D. Expect a number array.
What are the different data types used in JavaScript? - ....ANSWER ...-ANSWER:
There are 8 basic data types in JavaScript:
1. Number for numbers of any kind: integer or floating-point, integers are limited by
±((2^53)-1).
2. BigInt is for integer numbers of arbitrary length.
3. String for strings. A string may have zero or more characters, there's no separate
single-character type.
4. Boolean for true/false.
5. NULL for unknown values - a standalone type that has a single value null. Note,
typeof null returns "object" even though it is NOT and object.
6. Undefined for unassigned values - a standalone type that has a single value undefined.
7. Object for more complex data structures.
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 3
, 8. Symbol for unique identifiers.
Which collections of data are ordered by a key? - ....ANSWER ...-ANSWER:
Map and set objects.
What is the proper syntax for adding placeholders in template literals? -
....ANSWER ...-ANSWER:
Use a dollar sign followed by curly brackets:
${expression}.
Additional Info:
let name = "John";
// embed a variable
alert( `Hello, ${name}!` ); // Hello, John!
// embed an expression
alert( `the result is ${1 + 2}` ); // the result is 3
Note this only works if you use backticks, `, and not single(') or double(") quotes
otherwise the results will be shown as literal, ie: Hello, ${name}!
How do you instantiate a value as a BigInt?
…FOR STUDENTS ONLY…©️2025 ALL RIGHTS RESERVED… 4
