//The JS "for in" statement loops through the properties of an Object:
//Syntax
for (key in object){
//code block to be executed
}
const person = {first_name: "John", last_name: "Doe", age:25};
let text = "";
for (let x in person) {
text += person[x]
}
//John Doe 25
// Example explained
- The for in loop iterates over a person object
- Each iteration returns a key (x)
- The key is used to access the value of the key
- The value of the key is person[x]
//For in over arrays
for (variable in array){
code
}
const numbers = [45,4,9]
let txt = "";
for (let x in numbers){
txt += numbers[x]
}
// 45
// 4
// 9
//NOTE: It is better to use a "for" loop, a "for of" loop, or "Array.forEach()" when the order matters
///Array.forEach()
//forEach() method calls a function (a callback function) once for each array element
const numbers = [45,4,9]
let txt = "" (or let arr = []);
numbers.forEach(myFunction);
function myFunction(value, index, array){
txt += value;
}
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