reversing a string, why the quotations?

Question

I saw another stackoverflow thread here

one of the answers given was

function reverse(s){
    return s.split("").reverse().join("");
}

so my question is, why are there quotation marks for split and join but not reverse?

Answer 1

That's because the 3 functions are different:

String.split( delimiter ); // delimiter = split by what

Array.reverse(); // reverse an array
                 // unlike other array functions such as sort() or join()
                 // there is no other option to specify because the function
                 // does only one thing only one way

Array.join( join_string ); // join_string = what string to insert
                           // between elements

Whenever you have doubts about how functions work read the documentation:

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/split
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reverse
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/join

Not all functions require one argument. Some take none. Some take two or three. Some have optional arguments.

Answer 2

reverse() is called on an array. The result of split("") being an array of letters (strings of one letter each to be precise).

Answer 3

.split("") Will spit a string based on a given parameter. in this case "" means no delimiter so it will split on each char and return an array of char. then reverse() method is call on that array. once it reversed then we have to join it back to the string. join("") will do that task for you. in this case "" means no delimiter for join so array will join each char together.