function 与 array.join -javascript 中的帮助

Question

so before anything my experience with JavaScript is not that much, I'm trying to make a function called hashtag_it with an array and i want to add # before every index in this array so when I call the function the output is going to be #programming,#code, i tried to use array.join method but it didn't really work

 function hashtag_it(my_array) { my_array = ['programming','code']; console.log(my_array.join('#')) } console.log(hashtag_it());

Answer 1

 const my_array = ['programming','code']; function hashtag_it() { return my_array.map(item => `#${item}`).join(','); } console.log(hashtag_it(my_array));

.join only joins by a separator after each element. You want to add # before each element. What I have changed is I have added map which simply appends # before each element and then you can use join(',') which joins each element using a , as a separator

References:

• join
• map

Answer 2

You have to add # to all the elements in the array and then join it. Simply using join won't add # to the first element.

 function hashtag_it(my_array) { my_array = ['programming', 'code']; new_array = my_array.map(el => "#" + el).join(",") return new_array } console.log(hashtag_it());

Answer 3

 const array = ["programming", "coding", "dogs"]; const tagIt = (arr) => { return arr.map(word => '#'+word).join(","); }; console.log( tagIt(array) );