iterate array javascript

array = [ 1, 2, 3, 4, 5, 6 ]; 
for (index = 0; index < array.length; index++) { 
    console.log(array[index]); 
} var colors = ['red', 'green', 'blue'];
	
	colors.forEach((color, colorIndex) => {
     console.log(colorIndex + ". " + color); 
    });var txt = "";
var numbers = [45, 4, 9, 16, 25];

numbers.forEach(function(value, index, array) {
  txt = txt + value + "<br>";
});
/* ES6 */
const cities = ["Chicago", "New York", "Los Angeles"];
cities.map(city => {
	console.log(city)
})
arr.forEach(function callback(currentValue [, index [, array]]) {
    // Ihr Iterator
}[, thisArg]);var colors = ["red","blue","green"];
for (var i = 0; i < colors.length; i++) {
    console.log(colors[i]);
}