2018-10-13 (Unknown point)

Q: What is BFC, role? How to trigger? Solve practical problems?

A: BFC: block-level formatting context, which refers to a separate block-level rendering area that only block-level box participates in, which has a set of rendering rules to constrain the layout of block-level boxes and is independent of the outside of the area.

The root element, the value of float does not have a value of None,overflow of Visible,display, is Inline-block, Table-cell, Table-caption, The value of position is absolute or fixed and can be implemented BFC

Solve the problem: prevent margin overlap, you can let the parent element wrap the floating child element, this is also overflow:hidden can clearly float. The generated BFC elements that are adjacent to the floating element cannot be overwritten with floating elements.

Q: Whatis the difference between link and @import?

A: @import can only load CSS. and link can load more.

difference in loading order: When a page is clipped (when viewed by the browser), the CSS referenced by the link is loaded at the same time, and the CSS referenced by @import waits until the page is fully downloaded and then loaded. So sometimes browsing @import loading CSS page when there will be no style (that is, flashing), the speed of the slow time is quite obvious.

The difference when using the DOM to control styles. When you use JavaScript to control the DOM to change the style, only the link tag is used, because @import is not controlled by the DOM (not supported).
Q: An HTTP request structure? (Request header Parameter)

A:

Q: A page from the input URL to the page load display completed, what happened to this process?

A: Check the browser cache, domain name resolution, initiating a TCP connection, three-time handshake--client sends HTTP request---the server makes the appropriate message --Read the page content, browser rendering , Parse HTML source, generate DOM tree, parse CSS style, JS interaction

2018-10-13 (Unknown point)