JavaScript Forms Validation Knowledge

JavaScript form Programming:

I. How to find form elements:

1.var Oform=document.getelementbyid ("Form1");

2.var oform=document.forms[form1]//is searched by name;

Two. Common features of form fields:

Disabled: This property is used to indicate whether a form control is available;

Form property: This property returns the form containing the field;

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

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

Blur event: Occurs when the form field loses focus, and then executes the onblur event handler;

Focus Event: The event occurs when the form field receives focus, followed by the onfocus event handler;

Three: Form submission, reset

Sumbit:oform Sumbit ();

Reset:oform Reset ();

Four. Get the value of the text box:

Length otext.value.length;

Five: Add element node, text node, delete element

Createlement,creattextnode,remove;

Six: Select the value of the check box: Select

Seven: Form validation Best Practices:

Must be helpful to the user;

Don't let people hate you;

Use HTML instead of JavaScript whenever possible

Show all errors at once;

Catch errors early;

Don't be too strict if you are unsure;

JavaScript Forms Validation Knowledge