what is happening in this simple attempt to write a code that prints a user-inputted number, multiplied by numbers up to 12

Question

//this is what I wrote:

var z = prompt("enter a number to find its multiplication table");
var end = z*12;
for (; z<=end; z+=z) {
document.write(z + " ");
}

/*how would you write a code that would multiply the number from the user by the numbers 1 to 12, and print each one? (i.e. 5 10 15 20 25 30 etc.)*/

Answer 1

var z = prompt("enter a number to find its multiplication table");
for (var i = 1; i <= 12; i++) {
document.write(z*i + " ");
}