امثلة عن أنواع البيانات JavaScript Data Types

2021-03-28
daafoor

مثال عن متغيرات من نوع نصي string:

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Strings</h2>

<p>You can use quotes inside a string, as long as they don't match the quotes surrounding the string:</p>

<p id="demo"></p>

<script>
var answer1 = "It's alright";
var answer2 = "He is called 'Johnny'";
var answer3 = 'He is called "Johnny"';

document.getElementById("demo").innerHTML =
answer1 + "<br>" + 
answer2 + "<br>" + 
answer3;
</script>

</body>
</html>

مثال عن متغير من نوع مصفوفة array وطباعة العنصر الأول:

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Arrays</h2>

<p>Array indexes are zero-based, which means the first item is [0].</p>

<p id="demo"></p>

<script>
var cars = ["Saab","Volvo","BMW"];

document.getElementById("demo").innerHTML = cars[0];
</script>

</body>
</html>

مثال عن متغير من نوع كائن object وطباعة محتوياته:

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript Objects</h2>

<p id="demo"></p>

<script>
var person = {
  firstName : "John",
  lastName  : "Doe",
  age     : 50,
  eyeColor  : "blue"
};

document.getElementById("demo").innerHTML =
person.firstName + " is " + person.age + " years old.";
</script>

</body>
</html>

مثال عن متغير من نوع غيرمعرف undefined:

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript</h2>

<p>The value (and the data type) of a variable with no value is <b>undefined</b>.</p>

<p id="demo"></p>

<script>
var car;
document.getElementById("demo").innerHTML =
car + "<br>" + typeof car;
</script>

</body>
</html>

مثال عن متغير من نوع فارغ empty :

<!DOCTYPE html>
<html>
<body>

<h2>JavaScript</h2>

<p>An empty string has both a legal value and a type:</p>

<p id="demo"></p>

<script>
var car = "";
document.getElementById("demo").innerHTML =
"The value is: " +
car + "<br>" +
"The type is: " + typeof car;
</script>

</body>
</html>