404 DM Interview Questions and Answers

Q1. Difference between union and union all in SQL?
Ans. 
Union combines and removes duplicates, Union All combines without removing duplicates.
• Union combines result sets and removes duplicates

• Union All combines result sets without removing duplicates

• Union is slower than Union All as it involves removing duplicates

• Example: SELECT column1 FROM table1 UNION SELECT column1 FROM table2;

• Example: SELECT column1 FROM table1 UNION ALL SELECT column1 FROM table2;
Answered by AI
Add your answer
Q2. How to show top 5 in pandas?
Ans. 
To show top 5 in pandas, use the nlargest() function.
• Use the nlargest() function with the 'n' parameter set to 5 to get the top 5 values in a pandas DataFrame.

• For example: df['column_name'].nlargest(5) will return the top 5 values in the specified column.
Answered by AI
Add your answer

Q1. If we have 3 numerical columns, which chart is a better representation these column?
Ans. 
A scatter plot is a better representation for 3 numerical columns.
• Use a scatter plot to show the relationship between the numerical columns.

• Scatter plots are effective for visualizing correlations and patterns in data.

• Each point on the plot represents a data point with values from all 3 columns.
Answered by AI
Add your answer

HackerRank Test, basic questions related to the profile.

Q1. Coding Interview with the team manager
Add your answer

Q1. What are synthetic Events?
Ans. 
Synthetic Events are events that are created by the browser to mimic real user events.
• Synthetic Events are used in React to handle events in a consistent manner across different browsers.

• They are created by React to wrap native browser events and provide additional functionality.

• Examples include onClick, onChange, and onSubmit events in React.
Answered by AI
Add your answer
Q2. What is event bubbling?
Ans. 
Event bubbling is the process where an event triggered on a child element is propagated up through its parent elements.
• Event bubbling allows a single event handler to be attached to a parent element, which will be triggered for all its children.

• When an event occurs on a child element, it first runs the event handlers on the child, then on its parent, and so on up the DOM tree.

• Event bubbling can be stopped using event.s
Answered by AI
Add your answer

Q1. About datorama explain how it works
Add your answer
Q2. More about digital marketing
Add your answer

HTML, HTML5 ,CSS , Bootstrap, javaScript

First there was aptitude round

The coding question was average level

Q1. Resumes and project related questions were asked
Add your answer
Q2. Explain you project
Add your answer
Q3. How to create external tab link
Ans. 
To create an external tab link, use HTML anchor tag with target attribute set to _blank.
• Use <a> tag in HTML with href attribute pointing to the external link

• Set the target attribute of the <a> tag to _blank to open the link in a new tab

• Example: <a href='https://www.example.com' target='_blank'>External Link</a>
Answered by AI
Add your answer