which of the method can not looping structure in javascript code example

Example 1: javascript loop

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
*/

Example 2: for in loop javascript

var person = {"name":"taylor","age":31};
for (property in person) {
	console.log(property,person[property]);
}
//name taylor
//age 31