which loop for array and wich loop for object? code example

Example 1: javascript loop through object example

var person={
 	first_name:"johnny",
  	last_name: "johnson",
	phone:"703-3424-1111"
};
for (var property in person) {
  	console.log(property,":",person[property]);
}

Example 2: iterate through object array javascript

for (var key in array) {
    var obj = myArray[key];
    // ...
}