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Introduction to JavaScript

JavaScript Kya Hai?

JavaScript (JS) ek programming language hai jo web pages ko interactive banati hai. Agar aap HTML ko ek ghar ka dhancha (structure) aur CSS ko uska rang-o-rogan (styling) samjhein, to JavaScript us ghar ki bijli hai. Ye buttons ko clickable banati hai, forms ko validate karti hai, aur content ko user ke action ke hisab se badalti hai.

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JavaScript 1995 mein Netscape ke ek engineer Brendan Eich ne banayi thi. Shuru mein iska naam LiveScript tha, lekin us waqt Java language ki mash'hoori ki wajah se iska naam badal kar JavaScript rakh diya gaya. Ye faisla marketing ke liye tha, lekin yaad rakhein, JavaScript aur Java do bilkul alag languages hain.

JavaScript web ke liye zaroori hai. Yeh HTML aur CSS ke saath mil kar kaam karti hai takeh websites static na rahen, balke zinda aur dynamic mehsoos hon.

Development Environment Setup Karna

JavaScript shuru karne ke liye aap ko kisi khaas software ki zaroorat nahi hai. Aap ke computer mein pehle se hi sab kuch maujood hai. Aap ko bas do cheezein chahiye:

  1. Ek Text Editor: Yahan aap apna code likhenge. Aap Notepad (Windows) ya TextEdit (Mac) istemal kar sakte hain, lekin behtar hai ke aap ek code editor jaise ke Visual Studio Code (VS Code) istemal karein. Ye code likhna asaan banata hai.
  2. Ek Web Browser: Yahan aap apne code ka result dekhenge. Google Chrome, Mozilla Firefox, ya Microsoft Edge, sabhi kaam karenge.

Har modern web browser mein ek 'console' hota hai. Yeh ek aesa tool hai jo developers ko code test karne aur errors dhundne mein madad deta hai. Aap ise F12 key daba kar ya right-click karke 'Inspect' aur phir 'Console' tab select karke khol sakte hain.

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Aapka Pehla JavaScript Code

Chalein, apna pehla JavaScript code likhte hain. Hum ek aesa program banayenge jo browser ke console mein "Hello, World!" display karega. Console mein message dikhana code ko test karne ka ek aam tareeqa hai.

Sab se pehle, apne computer par ek file banayein aur uska naam index.html rakhein. Is file mein neeche diya gaya HTML code copy-paste karein.

<!DOCTYPE html>
<html>
<head>
    <title>My First JS Program</title>
</head>
<body>

    <h1>Welcome to JavaScript</h1>

    <script>
        // Yeh humara JavaScript code hai
        console.log("Hello, World!");
    </script>

</body>
</html>

Ab is index.html file ko apne web browser mein kholein. Aap ko safhe par "Welcome to JavaScript" likha nazar aayega. Lekin JavaScript ka output kahan hai?

Uske liye, browser ka console kholein (F12 dabayein). Aap ko wahan "Hello, World!" likha hua milega.

Mubarak ho! Aap ne apna pehla JavaScript code successfully run kar liya hai.

Yahan console.log() ek function hai jo bracket ke andar di gayi cheez ko console mein print karta hai. Yeh code ki aazmaish ke liye ek bohot mufeed tool hai.

Ab jab ke aap ne buniyadi baatein seekh li hain, chalein apne ilm ko ek chotay se quiz ke zariye parkhein.

Quiz Questions 1/4

JavaScript ka buniyadi maqsad kya hai?

Quiz Questions 2/4

JavaScript kis ne banayi thi?

Aap ne JavaScript ki duniya mein apna pehla qadam rakh liya hai. Yahan se aap web development ke safar mein aage barh sakte hain.