for loop

• This is used for when working with arrays.

• Loops through a block of code number of times.

 const cars = ["BMW", "Volvo", "Saab", "Ford", "Fiat", "Audi"];

        let text = "";
        for (let i = 0; i < cars.length; i++) {
        text += cars[i] + ",";

        }
console.log(text);

output:BMW, Volvo, Saab, Ford, Fiat, Audi

for in

• It loops through the properties of an object.

• It iterates automatically based on a key and then the key is used to get that access value.

• We can use this for array also but when index matters use array.foreach()

• foreach() takes three arguments item value,item index, array itself

     const person = {fname:"John", lname:"Doe", age:25};
  
    let text = "";
    for (let x in person) {
      text += person[x] + " ,";
    } 
    console.log(text);
  
    Output: John , Doe , 25
  

for of

• It loops through the value of an iterable object.

• It loops over through the iterable datastructures like arrays,Strings,maps,nodelists and more.

     const cars = ["BMW", "Volvo", "Mini"];
  
            let text = "";
            for (let x of cars) {
            text += x + ",";
            }
            console.log(text);
  
    output: BMW,Volvo,Mini,