Фореш Индекс
const array1 = ['a', 'b', 'c'];
array1.forEach((element, index) => console.log(element, index));
noqta.tn
const array1 = ['a', 'b', 'c'];
array1.forEach((element, index) => console.log(element, index));const arraySparse = [1,3,,7]
let numCallbackRuns = 0
arraySparse.forEach((element) => {
console.log(element)
numCallbackRuns++
})
console.log("numCallbackRuns: ", numCallbackRuns)
// 1
// 3
// 7
// numCallbackRuns: 3
// comment: as you can see the missing value between 3 and 7 didn't invoke callback function.var arr = [1,2,3,4,5,6,7,8];
// Uses the usual "for" loop to iterate
for(var i= 0, l = arr.length; i< l; i++){
console.log(arr[i]);
}
console.log("========================");
//Uses forEach to iterate
arr.forEach(function(item,index){
console.log(item);
});var txt = "";
var numbers = [45, 4, 9, 16, 25];
numbers.forEach(myFunction);
function myFunction(value, index, array) {
txt = txt + value + "<br>";
}const iterable = [10, 20, 30];
for (const value of iterable) {
console.log(value);
}
// 10
// 20
// 30var keys = Object.keys(o); // Get an array of property names for object o
var values = [] // Store matching property values in this array
for(var i = 0; i < keys.length; i++) { // For each index in the array
var key = keys[i]; // Get the key at that index
values[i] = o[key]; // Store the value in the values array
}