Can you change an array to a number and then back to a number in Javascript?

You can get from the original number to an array via a string:

x = 789 ;

sx = new String( x ) ; // sx is a string, "789"

ax = sx.split("") ; // ax is an array of strings, [ "7", "8", "9" ]

rax = ax.reverse() ; // rax is an array of strings, [ "9", "8", "7" ]

srax = rasx.join("") ; // srax is a string, "987"

revx = new Number( srasx ) ; // revx is a number, 987

You don't have to use explicit String and Number constructors. You can generate a string from a number by adding an empty string to the number, and you can generate a number from a string by using the string in an expression that makes it clear that you want JavaScript to treat the string as a number -- for instance, subtracting 0 from the string, or multiplying the string by 1, or dividing the string by 1. (But adding a number to the string won't work -- that will convert the number to a string and concatenate that new string onto the original string, producing a new string.)

And of course you don't need all of those intermediate variables. You can do the whole thing in one statement if you want, like this:

x = 789;

revx = ( "" + x ) . split( "" ) . reverse( ) . join( "" ) - 0;

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