.join ( ) 仅适用于 console.log ( )

Question

When I use the console.log( ) function to join this array it returns the combined array, but when I use the .join( ) function outside of console.log( ), it does not combine the array. How do I combine this array to create a single string with no comma outside of console.log( )?

var string = stringArray.map(string => "&sources=" + string);
console.log(stringURL.join(''));

stringURL.join('');
console.log(stringURL);

Answer 1

.join() is a function that returns the joined string. So when you call it, it calculates the value and then returns it.

Store it in a variable.

var joinedString = stringURL.join('');

Answer 2

Your problem is that stringURL.join(''); does modify stringURL but give a new string. so the best is to make

var new_string = stringURL.join('');
console.log(new_string);

Answer 3

You can't have a variable name called string, it's protected. Change it to something else and it will work.

Here's a complete list of reserved keywords and here is an explanation from Mozilla MDN

var mappedString = stringArray.map(string => "&sources=" + string);
console.log(mappedString.join(''));

var joinedString = mappedString.join('')

console.log(joinedString);

That should do!