Answer:- You may collapse any element with Bootstrap collapsing elements without creating any JavaScript code or accordion markup. To automatically delegate control of a collapsible element in bootstrap, add data-toggle= "collapse" to the controller element along with a data-target or href.

Answer:- Its an auto-updating nav component that allows you to grab sections of the page based on where youre scrolling. Based on the scroll position, the .active class will update from one nav item to the next.

Answer:- In Bootstrap, Jumbotron is used to highlight contents. It enlarges the headline and provides a margin for the landing pages content. In order to implement Jumbotron in Bootstrap, create a container div with the .jumbotron class.

Answer:- When the user moves the mouse pointer over an element, the Tooltip component appears as a little pop-up box. The Popover component is a pop-up box that emerges when the user clicks on an element. The popover may hold a lot more information. The popover will show on the right side of the element by default whereas the tooltip will show on the top of the element by default.

Answer:- The popover will show on the right side of the element by default. To position the popover on the top, bottom, left, or right side of the element, use the data-placement attribute. When you click on the element again, the popover closes by default. However, the data-trigger="focus" attribute can be used to close the popover when the user clicks outside the element. Use the data-trigger attribute with the value "hover" if you want the popover to appear when you move the mouse cursor over the element.

Answer:- The properties of flexbox are: • Enable flex behaviors: To make a flexible container and convert direct children elements into flex items, use the "display" utility. Additional flex characteristics can be used to further customize flex containers and items.

Answer:- • Direction: You can use direction utilities to change the direction of a flex item in a flex container. It is not essential to create a horizontal class because it is set to row by default. To show the flex items horizontally, use .flex-row (side by side). To right-align the horizontal direction, use .flex-row-reverse. Use .flex-column to display flex items vertically (on top of each other), or .flex-column-reverse to display them in the other direction. • Justify content: To adjust the alignment of flex elements, use the.justify-content-* classes. Start (default), end, center, between, and around are all valid classes. • Align items: You can change the vertical alignment of single rows of flex items with the .align-items-* classes. .align-items-start, .align-items-end, .align-items-center, .align-items-baseline, and .align-items-stretch (default) are valid classes. • Align self: You can change the vertical alignment of a specific flex item with the .align-self-* classes. .align-self-start, .align-self-end, .align-self-center, .align-self-baseline, and .align-self-stretch (default) are valid classes. • Auto margins: You can easily add auto margins to flex items with .mr-auto which pushes items to the right, or by using .ml-auto which pushes items to the left. • Grow: You can use .flex-grow-1 on a flex item to take up the unused space. In the example below, the second flex item uses all the available space since we have used the .flex-grow-1 class with the second flex item. You can use .flex-shrink-1 on a flex item to make it shrink if required. • Fill: You can use .flex-fill on flex items to make them into equal widths. • Wrap: With .flex-nowrap (default), .flex-wrap, or .flex-wrap-reverse, you can control how flex items wrap in a flex container. • Order: With the .order classes, you can change the visual order of a given flex item(s). The number of valid classes ranges from 0 to 12, with the lowest number having the highest importance (order-1 is shown before order-2, etc..). • Align content: You can change the vertical alignment of gathered flex items with the .align-content-* classes. .align-content-start (default), .align-content-end, .align-content-center, .align-content-baseline, and .align-content-stretch are valid classes.

Answer:- The following three rules should be strictly kept in mind while using Grids in Bootstrap:- • A rows immediate child must be a Column. • Rows are just used to contain Columns and are not utilized for anything else. • Rows should be put within a container.

Answer:- MySQL server is an open-source relational database management system (RDBMS) backed by oracle, based on SQL. Usually assessed using PHP. It is written in C, C++ language.

Answer:- These MySQL interview questions are best suited for beginners and intermediate users. • Mysql server is fast, reliable and easy to use • Protects sensitive data from intruders • Scalable and can handle huge amount of data • Compatible with almost every OS • PHP friendly • Large and extensive community support

Answer:- Listed below are disparate MySQL table: • MyISAM – default database engine • Heap – used for fast database access • Merge – removes the size limitation from MYISAM tables • InnoDB – supports transaction using COMMIT and Rollback • ISAM – deprecated and removed from version 5.x

Answer:- It is one of the most dealt MySQL interview questions • From and Joins • Where • Group by • Having • Select • Order By • Limit

Answer:- This MySQL interview questions could be answered in the below-mentioned way: • Inner Join : SELECT column_name(s) FROM table1 INNER JOIN table 2 ON table1.column_name = table2.column_name; • Left Join: SELECT column_name(s) FROM table1 LEFT JOIN table2 ON table1.column_name = table2.column_name; • Right Join: SELECT column_name(s) FROM table1 RIGHT JOIN table2 ON table2.column_name = table2.column_name;

Answer:- Now this question is one of the MySQL interview questions that should be understood carefully. • Use Indexes • Don’t use “*” • Avoid unnecessary columns • Use DISTINCT and Union solely if necessary • Use short table aliases • Avoid wildcard (%) at the start of LIKE pattern