Notes for important PHP-HTML knowledge

Important knowledge points of PHP-HTML 1. Using frameset, frame and iframe also realize Multi-Window

2. Use the useing distance usemap on the image to implement button jump. ------ 8th end set

3. The form must have names and values, because during packet capture, you can find that you must submit them.

4. fieldset tag --> legend, lable

5. You can only use margin-top and margin-left to locate the p Distance from the page margin.

6. Position the distance between elements in p and the p margin in padding-top and padding-left.

7. The default hyperlink is link. You can set hover attributes and visited.

8. Four selector priorities: id selector (#)> class selector (.)> html selector> wildcard selector (*)

9. Parent and Child selector, such as # id1 span {}-----> similar to a. clas1 {}; a. clas2 {}
You can also # id1 span. Not necessarily only a level 1.
(1) the parent-child selector can have multiple levels (but not three layers in actual development)
(2) Strict hierarchical relationships
(3) the parent-child selector is not limited to any type selector.
. S1 # id span
P # id. s2

10. An element can have both the id selector and class selector.
For example

11. An element can have at most one id selector, but multiple class selectors
For example
Note: When two class selectors conflict, the class selector written in the css file prevails.

12. We can write a part of the selector in a css file independently.
For example,. s1,. s2,. s3 {}

13. In-row elements and block elements
(1) an element in a row occupies only the width of its content and does not occupy the entire line.
(2) The Block Element occupies the entire line regardless of its content and is displayed with a line break.
==>> Common in-row elements include
==>> Common fast elements include

14. Line Elements and block elements can be converted to each other. Display: inline -- block

15. CSS box model: 13th margin, border, and padding

16. Pay attention to the default margin of some elements. Therefore, you must remove it. For example, ul

17. Positioning
==> Relative positioning: relocates the position to which the element should be displayed.
Standard stream, but cannot be occupied
==> Absolute positioning: locate the element closest to the element that is out of the standard stream, as shown in figure
If there is no parent element (or there is a parent element, but the parent element is not out of the standard stream ),
It is located relative to the upper left corner of the body.
==> Fixed positioning: Always positioned in the upper left corner of the window
==> The left top attribute has no effect on static. sattic is located based on margin_left and margin_top.
==> Z_index is used to set the stacked attribute when the object (p) is displayed. The smaller the z-index

18. The value of height and width is invalid for the element in the row. Unless converted to float or (display: block)

19. The cute house at the end of episode 20th has two areas worth learning for. One is to link the dynamic background image on the menu bar,
Second, only the lower border is displayed in the input box, and other borders are not displayed.