Four Different For Loooops!

Author: Doe Hoon LEE

Today, we are going to learn about for loop!

There are different ways to loop through arrays. Let me introduce four of them here.

Here is the sample Array that we are going to use!

var personArray = [
    {"name": "John Doe", "age": 20},
    {"name": "Jane Doe", "age": 19},
];

Regular For Loop!

for (let i=0; i < personArray.length; i++) {
    console.log(`His/her name is ${personArray[i].name}. He/She is ${personArray[i].age} years old.`);
}

For…Of

for (const person of personArray) {
    console.log(`His/her name is ${person.name}. He/She is ${person.age} years old.`);
}

For…In

for (const person in personArray) {
    console.log(`His/her name is ${personArray[person].name}. He/She is ${personArray[person].age} years old.`);
}

forEach()

personArray.forEach(person => {
    console.log(`His/her name is ${person.name}. He/She is ${person.age} years old.`);
})