FreeCodeCamp.com - Basic JavaSript - Iterate with JavaScript For Loops
Link to FreeCodeCamp
You can run the same code multiple times by using a loop.
You can run the same code multiple times by using a loop.
The most common type of JavaScript loop is called a "
for loop
" because it runs "for" a specific number of times.
For loops are declared with three optional expressions separated by semicolons:
for ([initialization]; [condition]; [final-expression])
The
initialization
statement is executed one time only before the loop starts. It is typically used to define and setup your loop variable.
The
condition
statement is evaluated at the beginning of every loop iteration and will continue as long as it evaluates to true
. When condition
is false
at the start of the iteration, the loop will stop executing. This means if condition
starts as false
, your loop will never execute.
The
final-expression
is executed at the end of each loop iteration, prior to the next condition
check and is usually used to increment or decrement your loop counter.
In the following example we initialize with
i = 0
and iterate while our condition i < 5
is true. We'll increment i
by 1
in each loop iteration with i++
as our final-expression
.var ourArray = [];
for (var i = 0; i < 5; i++) {
ourArray.push(i);
}
ourArray
will now contain [0,1,2,3,4]
.Instructions
Use a
for
loop to work to push the values 1 through 5 onto myArray
.
Sollution
// Example
var ourArray = [];
for (var i = 0; i < 5; i++) {
ourArray.push(i);
}
// Setup
var myArray = [];
// Only change code below this line.
for (i = 1; i < 6; i++) {myArray.push(i);}
Komentáře
Okomentovat