1. If the checked attribute is null, true, false, or any value is checked, no matter whether the checked attribute is assigned to it or not.

2. Set the name of the check box to be the same to set the check box to the same group.

3 Cli:

①mkdir: Create a directory

  • /mkdir a b c: Create a peer directory
  • /mkdir -p aa/bb/cc: creates a directory recursively

②touch: change the timestamp of the file, or create a new file that does not exist

  • /-a Changes the access time
  • /m Changes the change time
  • /-t Specifies the date and time

4. Browser kernel

  • IE browser kernel: Trident kernel, also known as IE kernel;
  • ②Chrome browser kernel: collectively known as Chromium kernel or Chrome kernel, formerly Webkit kernel, is now Blink kernel;
  • ③Firefox browser kernel: Gecko kernel, commonly known as Firefox kernel;
  • Safari browser kernel: Webkit kernel;
  • ⑤Opera browser kernel: it was originally its own Presto kernel, then Webkit, and now Blink kernel;
  • ⑥360 browser, Cheetah browser kernel: IE+Chrome dual kernel;
  • ⑦ Sogou, Roam, QQ browser kernel: Trident (compatible mode) +Webkit (high-speed mode);
  • ⑧ Baidu browser, Windows of the world kernel: IE kernel;
  • ⑨2345 browser kernel: It used to be IE kernel, now it is IE+Chrome kernel;

5. A Link attributes;

  • Href: set the link URL, relative path or absolute path.

  • ② Target: displays the connected window or frame;

  • (3) Open the link in a new window.

  • ④_self: open the link in the current window;

  • ⑤_parent: Open links in the parent window;

  • ⑥_top: open the link in the rating window;

  • ⑦framename: window name;

  • ⑧ Name: hyperlink, create a bookmark within the document;

  • ⑨ Title: Sets the text description of the hyperlink (displayed when the mouse is hovering).

6. Table unit:

  • A table whose cells span two columns:
<table border="1">
  <tr>
    <th>Month</th>
    <th>Savings</th>
  </tr>
  <tr>
    <td colspan="2">January</td>
  </tr>
  <tr>
    <td colspan="2">February</td>
  </tr>
</table>
Copy the code
  • Table cells spanning two rows:

7. The form of the method.

Method =”get”

  • This method appends form data to the URL as name-value pairs.Copy the code
  • After submitting the form this way, the URL of the resulting page can be bookmarked (the URL contains parameters) for future access.Copy the code
  • Limited by URL length (which varies from browser to browser), this method cannot submit more than a certain amount of data. Therefore, when there is too much data, it is difficult to ensure that all the data is being sent correctly.Copy the code
  • Never use GET method to transfer sensitive information such as password! (The emitted data will be displayed in the browser address bar)Copy the code

Method =”post”

  • This method uses THE HTTP POST method to send form data.Copy the code
  • When you submit the form using the POST method, the URL of the resulting page is unbookable (the URL contains no parameters).Copy the code
  • The POST method is more robust and secure than the GET method, and there is no limit on data size.Copy the code

8. The label for attribute

The for property is essentially binding the label to the form control, and the main difference is that if I have an input field, if I want to select the input field to get focus, if I only have input, I can only select the input field, but if I add label, and bind the label to the input, You can also select the input box by clicking label.

User name without label: <input type="text" name="" id=""> <br> <label for="text">Copy the code

9. About CSS property inheritance;

  • Not inheritable: Display, margin, border, padding, background, height, min-height, Max – Height, min-width, max-width, overflow, position, left, right, top, Bottom, Z-index, float, clear, table-layout, vertical-align, Page-break-After, Page-bread-before and Unicode-bidi.
  • All elements are inheritable: visibility and cursor.
  • Inline elements are inheritable: Word-spacing, word-spacing, word-spacing, word-spacing, word-spacing, word-spacing, word-spacing, word-spacing, word-spacing, word-spacing Font family, font size, font style, font variant, font weight, text-decoration, text-transform, direction.
  • Block elements are inheritable: text-indent and text-align.
  • List elements are inheritable: list-style, list-style type, list-style position, list-style image.
  • Table elements can be inherited: border-collapse.
  • Inheritable means that if the parent node sets the property, the child node can inherit the property