In this practice code how do you tell when the number is used to identify the number in the string

Question

I'm trying to get a better understanding of going to use the number to identify another number in the string var x =[1,3,5,8]; var temp = x[x.length -1]; x[x.length -] = x[0]; x[0] = temp; console.log(x);

Answer 1

there is no string in your code. Also please mention language name in tags.

Can you also elaborate more on what you are really trying to understand here ?