JS For Of Loop - thelastmile/FreeCodeCamp GitHub Wiki
JavaScript For of Loop
The for..of
statement creates a loop iterating over iterable objects (including Array, Map, Set, Arguments object and so on), invoking a custom iteration hook with statements to be executed for the value of each distinct property.
for (variable of object) {
statement
}
Description | |
---|---|
variable | On each iteration a value of a different property is assigned to variable. |
object | Object whose enumerable properties are iterated. |
MDN link | MSDN link | arguments @@iterator
Examples
Array
let arr = [ "fred", "tom", "bob" ];
for (let i of arr) {
console.log(i);
}
// Output:
// fred
// tom
// bob
Map
var m = new Map();
m.set(1, "black");
m.set(2, "red");
for (var n of m) {
console.log(n);
}
// Output:
// 1,black
// 2,red
Set
var s = new Set();
s.add(1);
s.add("red");
for (var n of s) {
console.log(n);
}
// Output:
// 1
// red
Arguments object
// your browser must support for..of loop
// and let-scoped variables in for loops
function DisplayArgumentsObject()
{
for (let n of arguments) {
console.log(n);
}
}
DisplayArgumentsObject(1,"red");
// Output:
// 1
// red