Things to pay attention to in Javascript form validation_javascript tips

Javascript form programming:

1. How to find form elements:

1.var oForm=document.getElementById("Form1");

2.var oForm=document.forms[Form1]//Search by name;

2. Common characteristics of form fields:

disabled: This attribute is used to indicate whether a form control is available;

form attribute: This attribute returns the form containing fields;

blur(): This method causes the form field to lose focus;

focus(): This method causes the form field to gain focus;

blur event: This event occurs when the form field loses focus, and then the onblur event handler is executed;

focus event: This event occurs when the form field gains focus, and then the onfocus event handler is executed;

Three: Form submission, reset

sumbit: oForm sumbit();

reset: oForm reset();

4. Get the value of the text box:

length otext.value.length;

Five: Add element nodes, text nodes, delete elements

creatElement, creatTextNode, remove;

6: Check the value of the check box: select

Seven: Best practices for form validation:

Must be helpful to users;

Don’t be annoying;

Use HTML functionality instead of Javascript whenever possible

Show all errors at once;

Catch errors early;

Don’t be too strict if you are not sure;