JavaScript Array Basics

Array methods ko jaanne se pehle, chalo pehle JavaScript arrays ke kuch basic concepts samajh lein.

Array Kya Hota Hai?

Array ek collection of elements hota hai. Yeh ek single variable me multiple values ko store karne ka tarika hai.

For example, agar hume bohot saare fruits ke names ko ek list me store karna hai, toh hum array ka use kar sakte hain.Array ko declare karne ke major tarike hote hain jo aap niche code example se samaj sakte hain

Output:

Note:array ko banane ka dono tarike hi sahi hai apko jo sahi lage usse banayiye usme koi dikkat wali bat nahi hai.

Empty array:let emptyarr=[]; // empty array aise banaya jata hai

Accessing Array Elements

Ab array to ban gaya, lekin agar hume yeh jaana ho ki pehla fruit konsa hai, toh hum indexing ka use karte hain.

Indexing in JavaScript Arrays

JavaScript me indexing 0 se start hoti hai. Iska matlab hai ki pehla element hamesha index 0 par hota hai, doosra element index 1 par, aur aise hi aage.ise zero based indexing bhi kaha jata hai

output:

Array Length aur Indexing

• arr.length: arr.length array ke total elements ko batata hai. Yeh 1 se start hota hai, yani agar array me 4 elements hain, toh arr.length ki value 4 hogi.

• Indexing: Jaise ki maine bataya, indexing 0 se start hoti hai, toh agar array me 4 elements hain, unka index 0 se 3 tak hoga

Top 10 array methods:

Ab Aate Hai Humare Asli Mudde Pe: 10 Array Methods in JavaScript

Ab tak humne arrays ke basic concepts samajh liye hain. Ab hum JavaScript ke 10 array methods ke baare mein jaanenge jo aapko coding mein kaafi madad denge.

Iske liye hum tin arrays lenge jo RCB IPL team ke 11 players, unke corresponding runs aur wickets ko represent karte hain.

methods are

1. .push() - Add an Element at the End of an Array

.push() method array ke end me ek new element ko add karne ka kaam karta hai.

Example: Agar humare RCB team ko naye rules ke hisaab se 12th player ko include karna hai, toh hum .push() ka use kar sakte hain.

2.pop() - Remove an Element from the End and Return It

.pop() method array ke end se ek element ko remove karta hai aur usse return bhi karta hai.

Example: Agar rules ke hisaab se 12th man ko nikalna hai, toh hum .pop() ka use kar sakte hain.

3. .find() - Find the First Element that Satisfies a Condition

The .find() method array ke pehle element ko return karta hai jo provided condition ko satisfy karta hai. Is method ka use tab kiya jata hai jab aapko array me se pehla aisa element chahiye jo ek specific condition ko meet kare.

Example:
Mere chote bhai ko jaana hai ki starting se pehla khiladi jinhone 50 Ya usse se zyada wickets liye hain, usne exactly kitna wickets liya hai.
Toh, maine kaha, abhi batata hoon, .find() ka use karke.

4. .findIndex() - Find the Index of the First Element that Satisfies a Condition

The .findIndex() method array ke pehle element ka index return karta hai jo provided condition ko satisfy karta hai. Agar aapko index chahiye, jo kisi specific condition ko meet karta ho, toh aap .findIndex() ka use kar sakte hain.

Example:
Mere bhai ne poocha ki RCB ki team me starting line me pehla khiladi kaun hai jinhone 5000 se zyada runs banaye hain.
Toh maine kaha, "Abhi batata hoon, .findIndex() ka use karke."

5. .includes() - Checks if an Array Contains a Specific Value

The .includes() method checks whether a given value is present in an array. Agar value present hai toh yeh true return karta hai, aur agar nahi hai toh false return karta hai.

Example:
Mere bhai ko jaana tha ki uska favorite khiladi, Virat Kohli, aaj khel raha hai ki nahi.
Toh maine kaha, "Abhi batata hoon, .includes() ka use karke."

6. .some() - Checks if at Least One Element in the Array Passes a Given Condition

The .some() method array me kisi bhi element ko check karta hai aur agar koi ek element condition ko satisfy karta hai, toh yeh true return karta hai. Agar koi bhi element condition ko satisfy nahi karta, toh false return hota hai.

Example:
Mere chote bhai ko jaana tha ki RCB ki team me koi bhi bowler ne 100 se zyada wickets liya hai ki nahi.
Toh maine kaha, "Abhi batata hoon, .some() ka use karke."

7. .forEach() - Executes a Provided Function Once for Each Array Element

The .forEach() method ek provided function ko har array ke element pe execute karta hai. Iska use karte waqt aapko manually index se looping nahi karni padti, bas aap array ke har item par jo function chahte ho wo apply kar sakte ho.

Example:
Maan lo, humein har player ka name ko capital letters me print karwana hai. Toh hum .forEach() method ka use karke har player ke naam ko easily capital letters mein convert kar sakte hain.

8. .map() - Creates a New Array by Applying a Function to Each Element of the Original Array

The .map() method ek naya array banata hai, jisme provided function ko har element par apply kiya jata hai. Yeh method original array ko change nahi karta, balki ek new array return karta hai.

Example:
Mere chote bhai ne poocha, ki agar har player ki runs ko double karna ho, par original array ko change nahi karna ho, toh kya kiya jaye?
Toh maine kaha, "Kyu nahi! .map() ka use karke abhi kar deta hoon."

9. .filter() - Creates a New Array Containing Only the Elements that Pass a Given Condition

The .filter() method ek naya array banata hai jisme sirf wo elements hote hain jo given condition ko satisfy karte hain. Yeh method original array ko modify nahi karta, balki ek naya array return karta hai jisme sirf wo elements included hote hain jo condition ko pass karte hain.

Example:
Mere chote bhai ne poocha, ki ek array banana hai jisme wo sab runs hon jo 500 se zyada hain.
Toh maine kaha, "Abhi ho jaega, .filter() ko use karke."

const runs = [
    8004,653 , 799, 1559, 730, 0, 939, 306, 19, 0, 0
];
const above500=runs.filter(function(run){
    return run>500;
})
console.log(above500);
// output
// [ 8004, 653, 799, 1559, 730, 939 ]

10. .reduce() - Reduces an Array to a Single Value by Applying a Function to Each Element

The .reduce() method array ke sabhi elements ko ek single value mein reduce karne ke liye ek function apply karta hai. Yeh method array ke har element ko ek accumulator ke saath process karta hai aur final result ko return karta hai. Aap sum, maximum, minimum, ya koi bhi custom operation perform kar sakte ho.

Example:
Mere chote bhai ne poocha, "Bhaiya, bataiye to sab players milakar kitne wickets liye honge."
Toh maine kaha, "Reduce ka use karke abhi batata hoon."

conclusion:

JavaScript arrays are incredibly powerful, and mastering their built-in methods can make your coding journey much smoother. Whether it's manipulating data with .map(), filtering results with .filter(), or reducing values with .reduce(), these methods help write cleaner, more efficient, and readable code.

But do not memorize any method there are many more methods you just need to know them when needed for syntax you can google them .karte karte aa hi jata hai bas consistent raho.

Happy coding! 💻✨