loop through a javascript array 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: for in loop javascript

let array = [1,2,3,4,5,6,7,8,9,10]; 
// our array that we will use the for loop on
for (let i = 0; i < array.length; i++) { 
  // this loop will console log the element at array[i] starting at 0
  // and will continue looping for i < array.length 
  console.log(array[i]);
  // after each loop i will increase by 1
}

// this will console log
// 1
// 2
// 3
// 4
// 5
// 6
// 7
// 8
// 9
// 10

Example 3: javascript for loop[

for(i=0;i<=5;i++){
  console.log(i);}

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Cpp Example