ES6+ features

🔹 1. Spread Operator (…)

• 👉 Expands elements of an array or object into another array/object.

    // Arrays
    const arr1 = [1,2,3]
    const arr2 = [...arr1, 4,6]
    console.log(arr2) // [1,2,3,4,6]

    // Object
    const obj = {name: 'Sonam'}
    const newObj = {...obj, role: 'Developer'}
    console.log(newObj) // {name: 'Sonam', role: 'Developer'}

• ✅ Use case: Cloning, merging, passing multiple values quickly.

🔹 2. Rest Operator (…)

• 👉 Collects remaining items into an array/object. (Opposite of spread.)

    // functions
    function sum(...nums){
        return nums.reduce((acc, curr)=> {acc+curr}, 0)
    }

    // Destructing
    const [a,b, ...rest] = [10,20,30,40]
    console.log(a,b) // 10, 20
    console.log(rest) // [30,40]

-✅ Use case: Flexible function arguments, grouping leftovers.

🔹 3. Destructuring

• 👉 Extracts values from arrays or objects into variables.

    // Arrays
    const colors = ['red', 'blue', 'black']
    const [first, , third] = colors;     // red

    // Object
    const person = {name: 'Test', role: 'Tester'}
    const {name, role} = person
    console.log(name, role)             // Test, Tester

• ✅ Use case: Cleaner code, avoid repetitive property access.

🔹 Summary

• Spread (…) → expands values.
• Rest (…) → collects values.
• Destructuring → extracts values.