串联字符串节点

Question

I've the following code and its working if result[1] have length is 1 like following:

var url = redir[0] + 'value=' + encoURL + '& + result[1];

Now I have scenario when result have more entries 3 or five and I need to concatenate it to the string,there is nice way to do it instead of this ugly way

var url = redir[0] + 'value=' + encoURL + '& + result[1] + '& + result[2] + '& + result[3]  

and etc.

I have use lo-dash and underscore ...

Answer 1

From your example it looks as if you want all the results appended to the value, delimited by ampersands. If that is what you want then this will do what you need...

// get a copy of result, with the first element removed...
var newResult = result.slice(1);
var url = redir[0] + 'value=' + encoURL + (newResult.length ? "&" : "") + newResult.join("&");

join will concatenate all the values of newResult , delimited by an ampersand.

(newResult.length ? "&" : "") basically adds the first ampersand if there are any values in newResult , so it handles the possibility that newResult is empty. You could also put the join inside that conditional operator, but I did it like this as it's more readable, and it makes no difference to the end result.

I created newResult so you still have the original result array intact, in case you need it later.