normal for loop 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: for loop
// this is javascript, but can be used in any language
// with minor modifications of variable definitions
let array = ["foo", "bar"]
let low = 0; // the index to start at
let high = array.length; // can also be a number
/* high can be a direct access too
the first part will be executed when the loop starts
for the first time
the second part ("i < high") is the condition
for it to loop over again.
the third part will be executen every time the code
block in the loop is closed.
*/
for(let i = low; i < high; i++) {
// the variable i is the index, which is
// the amount of times the loop has looped already
console.log(i);
console.log(array[i]);
} // i will be incremented when this is hit.
// output:
/*
0
foo
1
bar
*/