Javascript Post Course Assessment

1. What is the correct way to write a JavaScript array?

Var txt = new Array ="tim","kim","jim";

Var txt = new Array("tim","kim","jim");

Var txt = new Array:1=("tim")2=("kim")3=("jim");

Var txt = new Array(1:"tim",2:"kim",3:"jim");

The correct way to write a JavaScript array is by using the syntax var txt = new Array("tim","kim","jim"). This creates an array named "txt" with three elements: "tim", "kim", and "jim".

Explanation

The correct way to write a JavaScript array is by using the syntax var txt = new Array("tim","kim","jim"). This creates an array named "txt" with three elements: "tim", "kim", and "jim".

2. To display text ''message' along with the value contained in variable msg, an alert box should be called via:

Call alert ('message' + msg);

Alert ('message' + msg);

AlertBox ('message' + msg);

All of the above

To display the text 'message' along with the value contained in the variable msg, the correct way is to call the alert box using the syntax alert ('message' + msg). This will concatenate the string 'message' with the value of the variable msg and display it in an alert box. The other options, such as call alert, alert, and alertBox, are incorrect syntax and will not display the desired result.

Explanation

To display the text 'message' along with the value contained in the variable msg, the correct way is to call the alert box using the syntax alert ('message' + msg). This will concatenate the string 'message' with the value of the variable msg and display it in an alert box. The other options, such as call alert, alert, and alertBox, are incorrect syntax and will not display the desired result.

3. Which command skips the rest of a case statement?

Return

Exit

Continue

Break

The correct answer is "break". In a case statement, the break command is used to exit the switch statement and skip the remaining cases. It is often used to prevent fall-through, where execution continues to the next case even after a match is found. By using break, the program will jump to the end of the switch statement, allowing it to continue executing the code after the switch block.

Explanation

The correct answer is "break". In a case statement, the break command is used to exit the switch statement and skip the remaining cases. It is often used to prevent fall-through, where execution continues to the next case even after a match is found. By using break, the program will jump to the end of the switch statement, allowing it to continue executing the code after the switch block.

4. Which event do you use to run something after the page has finished loading?

Onfinished

Onload

Onunload

Oncomplete

The correct answer is "onload". The "onload" event is used to run something after the page has finished loading. This event is commonly used to trigger functions or scripts that require the page's content to be fully loaded before executing. It ensures that all elements, including images and external resources, have been loaded and are ready to be manipulated or interacted with.

Explanation

The correct answer is "onload". The "onload" event is used to run something after the page has finished loading. This event is commonly used to trigger functions or scripts that require the page's content to be fully loaded before executing. It ensures that all elements, including images and external resources, have been loaded and are ready to be manipulated or interacted with.

5. In a JS statement, what is the difference between a++ vs ++a where a is a variable:

A++ increments the value of a by 1, ++a is incorrect

Both are same and increment the value of a by 1

Both increments the value of a by 1 but a++ does it after assignment and ++a does it before assignment

Both are wrong and will cause an error in the code

The difference between a++ and ++a is that a++ increments the value of a by 1 after the assignment, while ++a increments the value of a by 1 before the assignment.

Explanation

The difference between a++ and ++a is that a++ increments the value of a by 1 after the assignment, while ++a increments the value of a by 1 before the assignment.

6. How do you define a "for" loop which starts from 0, goes till 5 and increments by 1 after each iteration?

For (i

For i = 0 to 5 {…}

For (i = 0; i

The correct answer is "for (i = 0; i

Explanation

The correct answer is "for (i = 0; i

7. Which of these is not a comparison operator?

>

=

!=

The equal sign (=) is not a comparison operator, but an assignment operator. It is used to assign a value to a variable, rather than comparing two values. Comparison operators are used to compare values and include operators such as greater than (>), less than (=), less than or equal to (

Explanation

The equal sign (=) is not a comparison operator, but an assignment operator. It is used to assign a value to a variable, rather than comparing two values. Comparison operators are used to compare values and include operators such as greater than (>), less than (=), less than or equal to (

8. How do you create a function named coolFunction?

Function coolfunction () {}

Function=coolFunction()

Function:coolFunction(){}

Function coolFunction () {}

The correct answer is "function coolFunction () {}". This is the correct way to create a function named coolFunction in JavaScript. The function keyword is used to declare a function, followed by the function name (coolFunction in this case), parentheses for any parameters, and curly braces to enclose the function body.

Explanation

The correct answer is "function coolFunction () {}". This is the correct way to create a function named coolFunction in JavaScript. The function keyword is used to declare a function, followed by the function name (coolFunction in this case), parentheses for any parameters, and curly braces to enclose the function body.

9. How can you reference part of a string starting from 4th character and containing a total of 5 characters contained in var str? (e.g. from a string "hello world!", it should return "lo wo").

Str.substr(4,9);

Str.part(3,5);

Str.substr(3,5);

Str.part(4,9);

The correct answer is `str.substr(3,5)` because the `substr()` method in JavaScript is used to extract a portion of a string, starting from the specified index and containing the specified number of characters. In this case, `str.substr(3,5)` will start from the 4th character (index 3) and return a string with 5 characters.

Explanation

The correct answer is `str.substr(3,5)` because the `substr()` method in JavaScript is used to extract a portion of a string, starting from the specified index and containing the specified number of characters. In this case, `str.substr(3,5)` will start from the 4th character (index 3) and return a string with 5 characters.

10. What will the statement mentioned below will do? result = (testCond == 1) ? "pass" : "fail";

Will return error as this is not a valid statement in JS.

If testCond is equal to 1 then result will contain an array with two elements pass and fail.

If testCond is equal to 1 then result will contain string pass otherwise it will be set to fail.

Result will contain value of testCond if the testCond is equal to 1

The statement mentioned will assign the value "pass" to the variable "result" if the condition "testCond == 1" is true. Otherwise, it will assign the value "fail" to the variable "result".

Explanation

The statement mentioned will assign the value "pass" to the variable "result" if the condition "testCond == 1" is true. Otherwise, it will assign the value "fail" to the variable "result".

JavaScript Post Course Assessment