JavaScript-Developer-I Exam Dumps - Salesforce Developer Questions and Answers

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Questions 4

Refer to the following code:

What is the output of line 11?

Options:

[1,2]

["bar", "foo"]

["foo:1", "bar:2"]

["foo", "bar"]

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Questions 5

is below:

”Image

The JavaScript portion is:

01 function previewFile(){

02 const preview = document.querySelector(‘img’);

03 const file = document.querySelector(‘input[type=file]’).files[0];

04 //line 4 code

05 reader.addEventListener(“load”, () => {

06 preview.src = reader.result;

07 },false);

08 //line 8 code

09 }

In lines 04 and 08, which code allows the user to select an image from their local

computer , and to display the image in the browser?

Options:

04 const reader = new File();

08 if (file) URL.createObjectURL(file);

04 const reader = new FileReader();

08 if (file) URL.createObjectURL(file);

04 const reader = new File();

08 if (file) reader.readAsDataURL(file);

04 const reader = new FileReader();

08 if (file) reader.readAsDataURL(file);

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Questions 6

A developer is required to write a function that calculates the sum of elements in an

array but is getting undefined every time the code is executed. The developer needs to find

what is missing in the code below.

Const sumFunction = arr => {

Return arr.reduce((result, current) => {

Result += current;

), 10);

);

Which option makes the code work as expected?

Options:

Replace line 02 with return arr.map(( result, current) => (

Replace line 04 with result = result +current;

Replace line 03 with if(arr.length == 0 ) ( return 0; )

Replace line 05 with return result;

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Questions 7

A developer needs to debug a Node.js web server because a runtime error keeps occurring at one of the endpoints.

The developer wants to test the endpoint on a local machine and make the request against a local server to look at the behavior. In the source code, the server, js file will start the server. the developer wants to debug the Node.js server only using the terminal.

Which command can the developer use to open the CLI debugger in their current terminal window?