• Home
  • Jobs
  • Courses
  • Certifications
  • Companies
  • Online IDE
  • Login
  • Signup
MYTAT
  • Home
  • Jobs
  • Courses
  • Certifications
  • Companies
  • Online IDE
  • Login
  • Signup
JavaScript
  • JavaScript Introduction
  • JavaScript Where To
  • JavaScript Output
  • JavaScript Statements
  • JavaScript Syntax
  • JavaScript Comments
  • JavaScript Variables
  • JavaScript Let
  • JavaScript Const
  • JavaScript Operators
  • JavaScript Assignment
  • JavaScript Data Types
  • JavaScript Functions
  • JavaScript Objects
  • JavaScript Events
  • JavaScript Strings
  • JavaScript String Methods
  • JavaScript Numbers
  • JavaScript Number Methods
  • JavaScript Arrays
  • JavaScript Array Const
  • JavaScript Array Methods
  • JavaScript Sorting Arrays
  • JavaScript Array Iteration
  • JavaScript Date Objects
  • JavaScript Date Formats
  • JavaScript Get Date Methods
  • JavaScript Set Date Methods
  • JavaScript Math Object
  • JavaScript Random
  • JavaScript Booleans
  • JavaScript Comparison And Logical Operators
  • JavaScript If Else And Else If
  • JavaScript Switch Statement
  • JavaScript For Loop
  • JavaScript Break And Continue
  • JavaScript Type Conversion
  • JavaScript Bitwise Operations
  • JavaScript Regular Expressions
  • JavaScript Errors
  • JavaScript Scope
  • JavaScript Hoisting
  • JavaScript Use Strict
  • The JavaScript This Keyword
  • JavaScript Arrow Function
  • JavaScript Classes
  • JavaScript JSON
  • JavaScript Debugging
  • JavaScript Style Guide
  • JavaScript Common Mistakes
  • JavaScript Performance
  • JavaScript Reserved Words
  • JavaScript Versions
  • JavaScript History
  • JavaScript Forms
  • JavaScript Validation API
  • JavaScript Objects
  • JavaScript Object Properties
  • JavaScript Function Definitions
  • JavaScript Function Parameters
  • JavaScript Function Invocation
  • JavaScript Closures
  • JavaScript Classes
  • Java Script Async
  • JavaScript HTML DOM
  • The Browser Object Model
  • JS Ajax
  • JavaScript JSON
  • JavaScript Web APIs
  • JS Vs JQuery
  • Home
  • Courses
  • JavaScript
  • JavaScript Validation API

JavaScript Validation API

Previous Next

Constraint Validation DOM Methods

Property Description
checkValidity() Returns true if an input element contains valid data.
setCustomValidity() Sets the validationMessage property of an input element.

If an input field contains invalid data, display a message:

The checkValidity() Method

<input id="id1" type="number" min="100" max="300" required>
<button onclick="myFunction()">OK</button>

<p id="demo"></p>

<script>
function myFunction() {
  var inpObj = document.getElementById("id1");
  if (!inpObj.checkValidity()) {
    document.getElementById("demo").innerHTML = inpObj.validationMessage;
  }
}
</script>

Constraint Validation DOM Properties

Property Description
validity Contains boolean properties related to the validity of an input element.
validationMessage Contains the message a browser will display when the validity is false.
willValidate Indicates if an input element will be validated.



Practice Excercise Practice now

Validity Properties

The validity property of an input element contains a number of properties related to the validity of data:

Property Description
customError Set to true, if a custom validity message is set.
patternMismatch Set to true, if an element's value does not match its pattern attribute.
rangeOverflow Set to true, if an element's value is greater than its max attribute.
rangeUnderflow Set to true, if an element's value is less than its min attribute.
stepMismatch Set to true, if an element's value is invalid per its step attribute.
tooLong Set to true, if an element's value exceeds its maxLength attribute.
typeMismatch Set to true, if an element's value is invalid per its type attribute.
valueMissing Set to true, if an element (with a required attribute) has no value.
valid Set to true, if an element's value is valid.

Examples

If the number in an input field is greater than 100 (the input's max attribute), display a message:

The rangeOverflow Property

<input id="id1" type="number" max="100">
<button onclick="myFunction()">OK</button>

<p id="demo"></p>

<script>
function myFunction() {
  var txt = "";
  if (document.getElementById("id1").validity.rangeOverflow) {
    txt = "Value too large";
  }
  document.getElementById("demo").innerHTML = txt;
}
</script>

If the number in an input field is less than 100 (the input's min attribute), display a message:

The rangeUnderflow Property

<input id="id1" type="number" min="100">
<button onclick="myFunction()">OK</button>

<p id="demo"></p>

<script>
function myFunction() {
  var txt = "";
  if (document.getElementById("id1").validity.rangeUnderflow) {
    txt = "Value too small";
  }
  document.getElementById("demo").innerHTML = txt;
}
</script>



Practice Excercise Practice now

Previous Next
COMPANY
  • About us
  • Careers
  • Contact Us
  • In Press
  • People
  • Companies List
Products
  • Features
  • Coding Assessments
  • Psychometric Assessment
  • Aptitude Assessments
  • Tech/Functional Assessments
  • Video Assessment
  • Fluency Assessment
  • Campus
 
  • Learning
  • Campus Recruitment
  • Lateral Recruitment
  • Enterprise
  • Education
  • K 12
  • Government
OTHERS
  • Blog
  • Terms of Services
  • Privacy Policy
  • Refund Policy
  • Mart Category
Partner
  • Partner Login
  • Partner Signup

Copyright © RVR Innovations LLP 2025 | All rights reserved - Mytat.co is the venture of RVR Innovations LLP