iterating in javascript code example

Example 1: javascript loop through array

var data = [1, 2, 3, 4, 5, 6];

// traditional for loop
for(let i=0; i<=data.length; i++) {
  console.log(data[i])  // 1 2 3 4 5 6
}

// using for...of
for(let i of data) {
	console.log(i) // 1 2 3 4 5 6
}

// using for...in
for(let i in data) {
  	console.log(i) // Prints indices for array elements
	console.log(data[i]) // 1 2 3 4 5 6
}

// using forEach
data.forEach((i) => {
  console.log(i) // 1 2 3 4 5 6
})
// NOTE ->  forEach method is about 95% slower than the traditional for loop

// using map
data.map((i) => {
  console.log(i) // 1 2 3 4 5 6
})

Example 2: js loop through array

// ES6 for-of statement
for (const color of colors){
    console.log(color);
}

// Array.prototype.forEach
const array = ["one", "two", "three"]
array.forEach(function (item, index) {
  console.log(item, index);
});

// Sequential for loop
for (var i = 0; i < arrayLength; i++) {
    console.log(myStringArray[i]);
    //Do something
}

Example 3: for loop javascript

var i;
for (i = 0; i < 10 ; i++) {
  //do something
}

Example 4: for of loop syntax javascript

for (let step = 0; step < 5; step++) {
  // Runs 5 times, with values of step 0 through 4.
  console.log('Walking east one step');
}