PHP-HTMLhtml important knowledge points notes (must read)

1. Use frameset, frame and iframe to realize multiple windows

2. Use the mapping distance usemap on the picture to realize button jump. ------ Episode 8 End

3. The form must have a name and a value, because when capturing packets, you can find that they must be submitted

4.fieldset tag -> legend, label

5. You can only use margin-top and margin-left to position the div’s distance from the page margin.

6. padding-top and padding-left position the distance between the elements in the div and the div margin

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

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

9. Parent-child selector, such as #id1 span{}----->similar to a.clas1{};a.clas2{}
You can also #id1 span span. It doesn't have to be just one level.
(1) Parent-child selectors can have multiple levels (but in actual development, do not exceed three levels)
(2) There is a strict hierarchical relationship (3) Parent-child selectors are not limited to any type of selector
.s1 #id span
div #id .s2

10. An element can have both an id selector and a class selector.
For example <span class="s1" id="news">Hehe</span>

11. An element can have at most one id selector, but can have multiple class selectors, such as <span class="cls1 s1">呵</span>
Special note: When two class selectors conflict, the latter class selector in the CSS file will prevail.

12. We can write a separate copy of the common selectors in a CSS file, such as .s1, .s2, .s3{}

13. Inline elements and block elements (1) Inline elements only occupy the width required to display their own content and do not occupy the entire line (2) Block elements occupy the entire line regardless of the size of their content and will wrap to display
==>> Common inline elements include <a><img><input>
==>> Common fast elements include <div><p>

14. Inline elements and block elements can be converted to each other. Use display:inline--block

15. CSS box model: Part 13, part 2, margin, border, padding

16. Note the default margins of some elements. So be careful to remove it. For example,

17. Positioning
==>Relative positioning: Reposition the element relative to where it should be displayed. Although it is out of the standard flow, the position is not given up and cannot be occupied.
==>Absolute positioning: Position the element closest to the element that is out of the standard flow. If there is no parent element (or there is a parent element, but the parent element is not out of the standard flow),
Then position relative to the upper left corner of the body
==>Fixed positioning: always positioned in the upper left corner of the window
==>left top attribute has no effect on static, sattic is positioned by margin_left and margin_top
==>z_index is used to set the stacking properties when the object (div) is displayed. The smaller the z-index, the lower it is.

18. The height and width values ​​of inline elements are invalid. Unless converted to float or (display:block)

19. There are two things worth learning from the cute house at the end of episode 20. One is the dynamic background image of the link menu bar.
Second, the input box only displays the bottom border, and other borders are not displayed

The above PHP-HTMLhtml important knowledge points note (must read) is all the content that the editor shares with you. I hope it can give you a reference. I also hope that you will support 123WORDPRESS.COM.