In my last blog we went over the two more commonly used loops: for loop and while loop. Now let's take a look at two newer loops that are now being used: For in and For of loops.
For Of Loop
The for/of lets you loop over data structures that are iterable such as Arrays, Strings, and others.
The syntax of a for/of loop is:
for (variable of iterable) {
statement
}
Example
Let's say we have the following array
const myArr = ["dog","cat","snake","mouse"];
If we wanted to go through and print every element of this array we can do that easily using a for/of loop:
const myArr = ["dog","cat","snake","mouse"];
for(const element of myArr){
console.log(element)
}
/* output
dog
cat
snake
mouse
*/
this is a much easier and cleaner way to iterate through an array than using a regular for loop:
const myArr = ["dog","cat","snake","mouse"];
for(let i=0;i<myArr.length;i++){
console.log(myArr[i])
}
The for/of loop is create for iterating through arrays but what about the objects? That is where our next loop comes into play:
For In Loop
The for/in loop is used to loop through the properties of an object. The syntax of a for/in loop is:
for (variable in object){
statement
}
Example
What if we wanted to iterate through the following object and print the values of each key?
const basketballTeam = {
Guard:"Curry",
Forward:"Leonard",
Center:"Boban"
}
You can easily do this with a for/in loop
const basketballTeam = {
Guard:"Curry",
Forward:"Leonard",
Center:"Boban"
}
for(const property in basketballTeam) {
console.log(basketballTeam[property])
}
/*Output
Curry
Leonard
Boban
*/
If you only wanted to print the keys you could do that too:
const basketballTeam = {
Guard:"Curry",
Forward:"Leonard",
Center:"Boban"
}
for(const property in basketballTeam) {
console.log(property)
}
/*Output
Guard
Forward
Center
*/
Top comments (0)