For each & map

array.Foreach()

• The foreach() methods calls a function for each element in a array,it not executed for empty elements

const number = [33,44,55,66,77]
number.forEach(value);
function value(i,j,k){
    console.log(i,j,k);
}

• if we call foreach before declation in expresss & airrow function we get reference error.

• the best practice is to use declaration function

• this doen't return any values.if we return it will give undefined

• the foreach will give values , indexnumber,and array this three values by default if we want those.

• It's primarily used for executing side effects like logging to the console or modifying external variables.

array.map()

• map() creates a new array from caliing function for every array element,dont execute the function for empty elements

• does not change the orginial array

• it returns values

• same syntax as foreach
  

const numbers = [1, 2, 3, 4, 5];
const doubled = numbers.map(num => num * 2);
console.log(doubled); // Outputs: [2, 4, 6, 8, 10]

• It's perfect for data transformation without mutating the original array.