Praktilised koodinäited kasutades JavaScript
James Hartman
Näide nr 1: JavaSkripti korrutustabel
Looge lihtne korrutustabel, küsides kasutajalt soovitud ridade ja veergude arvu.
Lahendus:
<html>
<head>
<title>Multiplication Table</title>
<script type="text/javascript">
var rows = prompt("How many rows for your multiplication table?");
var cols = prompt("How many columns for your multiplication table?");
if(rows == "" || rows == null)
rows = 10;
if(cols== "" || cols== null)
cols = 10;
createTable(rows, cols);
function createTable(rows, cols)
{
var j=1;
var output = "<table border='1' width='500' cellspacing='0'cellpadding='5'>";
for(i=1;i<=rows;i++)
{
output = output + "<tr>";
while(j<=cols)
{
output = output + "<td>" + i*j + "</td>";
j = j+1;
}
output = output + "</tr>";
j = 1;
}
output = output + "</table>";
document.write(output);
}
</script>
</head>
<body>
</body>
</html>
Näide nr 2: JS-vormide näide:
Loo näidisvormiprogramm, mis kogub kasutajalt eesnime, perekonnanime, meili, kasutajatunnuse, parooli ja kinnitab parooli. Kõik sisendid on kohustuslikud ja sisestatud e-posti aadress peab olema õiges vormingus. Samuti peaksid parooli ja parooli kinnitamise tekstikasti sisestatud väärtused olema samad. Pärast kasutamise kinnitamist JavaScript, Väljundis kuvatakse õiged veateated punase värviga just selle tekstikasti kõrval, kus viga on.
Lahendus lähtekoodiga:
<html>
<head>
<title>Form Validation</title>
<script type="text/javascript">
var divs = new Array();
divs[0] = "errFirst";
divs[1] = "errLast";
divs[2] = "errEmail";
divs[3] = "errUid";
divs[4] = "errPassword";
divs[5] = "errConfirm";
function validate()
{
var inputs = new Array();
inputs[0] = document.getElementById('first').value;
inputs[1] = document.getElementById('last').value;
inputs[2] = document.getElementById('email').value;
inputs[3] = document.getElementById('uid').value;
inputs[4] = document.getElementById('password').value;
inputs[5] = document.getElementById('confirm').value;
var errors = new Array();
errors[0] = "<span style='color:red'>Please enter your first name!</span>";
errors[1] = "<span style='color:red'>Please enter your last name!</span>";
errors[2] = "<span style='color:red'>Please enter your email!</span>";
errors[3] = "<span style='color:red'>Please enter your user id!</span>";
errors[4] = "<span style='color:red'>Please enter your password!</span>";
errors[5] = "<span style='color:red'>Please confirm your password!</span>";
for (i in inputs)
{
var errMessage = errors[i];
var div = divs[i];
if (inputs[i] == "")
document.getElementById(div).innerHTML = errMessage;
else if (i==2)
{
var atpos=inputs[i].indexOf("@");
var dotpos=inputs[i].lastIndexOf(".");
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=inputs[i].length)
document.getElementById('errEmail').innerHTML = "<span style='color: red'>Enter a valid email address!</span>";
else
document.getElementById(div).innerHTML = "OK!";
}
else if (i==5)
{
var first = document.getElementById('password').value;
var second = document.getElementById('confirm').value;
if (second != first)
document.getElementById('errConfirm').innerHTML = "<span style='color: red'>Your passwords don't match!</span>";
else
document.getElementById(div).innerHTML = "OK!";
}
else
document.getElementById(div).innerHTML = "OK!";
}
}
function finalValidate()
{
var count = 0;
for(i=0;i<6;i++)
{
var div = divs[i];
if(document.getElementById(div).innerHTML == "OK!")
count = count + 1;
}
if(count == 6)
document.getElementById("errFinal").innerHTML = "All the data you entered is correct!!!";
}
</script>
</head>
<body>
<table id="table1">
<tr>
<td>First Name:</td>
<td><input type="text" id="first" onkeyup="validate();" /></td>
<td><div id="errFirst"></div></td>
</tr>
<tr>
<td>Last Name:</td>
<td><input type="text" id="last" onkeyup="validate();"/></td>
<td><div id="errLast"></div></td>
</tr>
<tr>
<td>Email:</td>
<td><input type="text" id="email" onkeyup="validate();"/></td>
<td><div id="errEmail"></div></td>
</tr>
<tr>
<td>User Id:</td>
<td><input type="text" id="uid" onkeyup="validate();"/></td>
<td><div id="errUid"></div></td>
</tr>
<tr>
<td>Password:</td>
<td><input type="password" id="password" onkeyup="validate();"/></td>
<td><div id="errPassword"></div></td>
</tr>
<tr>
<td>Confirm Password:</td>
<td><input type="password" id="confirm" onkeyup="validate();"/></td>
<td><div id="errConfirm"></div></td>
</tr>
<tr>
<td><input type="button" id="create" value="Create" onclick="validate();finalValidate();"/></td>
<td><div id="errFinal"></div></td>
</tr>
</table>
</body>
</html>
Näide nr 3: hüpikaken, kasutades sündmust:
Kuvage lihtne teade "Tere tulemast!!!" demoveebilehel ja kui kasutaja hõljutab kursorit sõnumi kohal, peaks ilmuma hüpikaken sõnumiga "Tere tulemast minu veebilehele!!!".
Lahendus:
<html>
<head>
<title>Event!!!</title>
<script type="text/javascript">
function trigger() {
document.getElementById("hover").addEventListener("mouseover", popup);
function popup() {
alert("Welcome to my WebPage!!!");
}
}
</script>
<style>
p{
font-size: 50px;
position: fixed;
left: 550px;
top: 300px;
}
</style>
</head>
<body onload="trigger();">
<p id="hover">Welcome!!!</p>
</body>
</html>
