Web Development Stuff

< input type = "file" class = "form-control" name = "productPhoto1" onchange = " preview ('productPhoto1Src'); " />         function preview ( imgSrc ) {           var fileBlob = URL . createObjectURL ( event . target . files [ 0 ]);           $ ( "#" + imgSrc ). attr ( 'src' , test123 );                   }

  // App.js import React, { useState } from "react"; import { Dropdown, Option } from "./Dropdown"; export default function App() {   const [optionValue, setOptionValue] = useState("");   const handleSelect = (e) => {     console.log(e.target.value);     setOptionValue(e.target.value);   };   return (     <div>       <h1>Which service are you interested in?</h1>       <Dropdown         formLabel="Choose a service"         buttonText="Send form"         onChange={handleSelect}         action="https://jsonplaceholder.typicode.com/posts"       >         <Option selected value="Click to see options" />         <Option value="Option 1" />         <Option value="Option 2" />         <Option...

  function ValidateEmail(mail) { if (/^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/.test(myForm.emailAddr.value)) { return (true) } alert("You have entered an invalid email address!") return (false) }   function ValidateEmail(email) { var mailformat = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/; if(email.match(mailformat)){ alert ("valid"); } }

    < script src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js" > </ script > < form action = "upload.php" enctype = "multipart/form-data" method = "POST" id = "uploadform" > < input id = "openFile" name = "img" type = "file" /> </ form >   <script> $( document ).ready( function ( ) { $( '#openFile' ).on( 'change' , function ( evt ) { console .log( this .files[ 0 ].size); ///File size      var filename=   this .files[ 0 ];      extension = filename.split( '/' ).pop();    // File Type Extension       }); });   </script>    ------------------------------------------------------------------------------- <form id="form1" runat="server"> <input type='file' id="imgInp" /> <img id="blah" src="#" alt="your image...

  localStorage only supports strings. Use JSON.stringify() and JSON.parse() . var names = []; names[ 0 ] = prompt( "New member name?" ); localStorage .setItem( "names" , JSON .stringify(names)); //... var storedNames = JSON .parse( localStorage .getItem( "names" ));

  function RadionButtonSelectedValueSet ( name, SelectdValue ) { $( 'input[name="' + name+ '"][value="' + SelectdValue + '"]' ).prop( 'checked' , true ); }

                            var dob=$("#dob").val();               var new_dob=dob.split("-").reverse().join("-");               $("#dob").val(new_dob);

  $( "#myElem" ).show(); setTimeout ( function ( ) { $( "#myElem" ).hide(); }, 5000 );

  var s1 = "foobar" ; var s2 = s1.substring( 1 ); alert(s2); // shows "oobar"

  var form = $( '#fileUploadForm' )[ 0 ]; var data = new FormData(form); data.append( "CustomField" , "This is some extra data, testing" ); $( "#btnSubmit" ).prop( "disabled" , true ); $.ajax({ type : "POST" , enctype : 'multipart/form-data' , url : "upload.php" , data : data, processData : false , contentType : false , cache : false , timeout : 600000 , success : function ( data ) { console .log(); },

  This JavaScript exception invalid assignment to const occurs if a user tries to change a constant value. Const declarations in JavaScript can not be re-assigned or re-declared. Message: TypeError: invalid assignment to const "x" (Firefox) TypeError: Assignment to constant variable. (Chrome) TypeError: Assignment to const (Edge) TypeError: Redeclaration of const 'x' (IE) Error Type: TypeError Cause of Error: A const value in JavaScript is changed by the program which can not be altered during normal execution. < script >      const GFG = "This is GFG";      // Error here      GFG = "This is GeeksForGeeks";  </ script >   Output(in console): TypeError: Assignment to const  

  HTML part : - < div id = "example" > < p > Original message: "{{ message }}" </ p > < p > Computed reversed message: "{{ reversedMessage }}" </ p > </ div >   JS Part : -   var vm = new Vue({ el : '#example' , data : { message : 'Hello' }, computed : { // a computed getter reversedMessage : function ( ) { // `this` points to the vm instance return this .message.split( '' ).reverse().join( '' ) } } })

  Type 1 Validation using Javascript : - <!DOCTYPE html> <html> <head>     <title>Indian Mobile No. Validation</title> </head> <body> <h1 style="text-align:center">Indian Mobile No. Validation</h1> <form>     <table align="center" border="30">              <tr>             <td>Mobile No.</td>             <td><input type="text" id="mobile" maxlength="10"  placeholder="Enter Your Mobile No."  /></td>         </tr>                  <tr>             <td colspan="2">                 <input type="button"...

    function changeContent ( ) { var opt= document .getElementById( 'test' ).options[ 0 ]; opt.value = 'box' ; opt.text = 'box' ; }

 In this post you will learn how to get value from form elements and how to validate whether it filled or not and selected or not . We are trying to show you all basic tags with validation . <!DOCTYPE html> <html> <head>     <title></title> </head> <body>     <h1>Pure Javascript Form Validation using form Element Name</h1>     <form name="myform">         <table align="center" border="30">             <tr>             <td>Gender</td>             <td>                 <input type="radio" name="gender" value="Female" />&nbsp;&nbsp;Female &nbsp;&nbsp;             ...