Summary of knowledge points related to forms and forms

1. form ：

1.1 The basic structure of the table

1.11 Properties of the table ****
cellspancing
cellpadding
border
align
bgcolor background
1.2 merge cell
Use colspan attribute ： Merge cells left and right
Use rowspan attribute ： Merge cells up and down
Pay attention to the correspondence between cells when merging cells
1.3 Complete table marking

2. Forms ：

2.1 Concept and function of forms
Forms ： It is used to collect user input data and submit the data to the server
**2.11 The composition of the form ：** A form has three basic form tags ： This contains the program used to process the form data URL And how to submit the data to the server .
Form field ： Contains a text box 、 Password box 、 Hidden fields 、 Multi-line text box 、 Check box 、 Radio buttons 、 Drop down the selection box and file upload box .
Form button ： Include submit button 、 Reset button and general button ;
Form labels stay <form></form>
function ： Used to declare a form , Define the scope of data collection , That is to say ＜form＞ and ＜/form＞ The data contained in it will be submitted to the server
grammar ：<form action="url" method="get" ></form> action=“” Server address method=“” get / post
2.12 Form field object
The form field contains a text box 、 Multi-line text box 、 Password box 、 Hidden fields 、 Check box 、 Checkboxes, drop-down boxes, etc , Used to collect data input or selected by users
The text box
A text box is a form object that allows visitors to enter their own content , It is usually used to fill in a single word or a short answer , Such as name 、 Address, etc .
Code format ：＜input type="text" name="..." size="..." maxlength="..." value="..."＞

2.13 Multi-line text box ：
It is also a form object that allows visitors to enter their own content , It just allows visitors to fill in long content .
Code format ：＜textarea name="..." cols="..." rows="..." ＞＜/textarea＞
2.14 Password box ：
Is a special text field , Used to enter a password . When a visitor enters text , The text will be replaced by asterisks or other symbols , The input text will be hidden .
Code format ： Code format ：＜input type=“password” name="…" size="…" maxlength="…“/＞
2.15 Hidden fields
Hidden fields are invisible elements used to collect or send information , For web visitors , Hidden fields are invisible . When the form is submitted , The hidden field will send the information to the server with the name and value defined when you set it .
Code format ：＜input type="hidden" name="..." value="..."＞
2.16 Check box
The check box allows more than one option to be selected among the options to be selected . Each check box is a separate element , Must have a unique name .
Code format ：＜input type=“checkbox” name="…" value="…"＞ Radio buttons
When the visitor is required to choose the only answer in the options to be selected , You need to use the radio box .
Code format ：＜input type="radio" name="..." value="..."＞ Must write the same name Value can be selected one at a time

2.17 File upload box
occasionally , Users need to upload their own files , The file upload box looks similar to other text fields , It's just that it also contains a browse button . Visitors can enter the path of the file to be uploaded or click the Browse button to select the file to be uploaded .
Code format ：＜input type="file" name="..." size="15" maxlength="100"＞
2.18 Drop down the selection box
The drop-down selection box allows you to set multiple options in a limited space .
Code format ：`＜select name="…" size="…" multiple＞
＜option value="…" selected＞…＜/option＞
…
＜/select＞
2.19 Form button
The form button controls the operation of the form
Submit button
The submit button is used to submit the entered information to the server .
Code format ：＜input type=“submit” name="…" value="…“＞
2.20 Reset button
The reset button is used to reset the form .
Code format ：＜input type=“reset” name=”…" value="…“＞
2.21 General buttons
General buttons are used to control the processing of other defined processing scripts .
Code format ：＜input type=“button” name=”…" value="…" οnclick="…"＞