Javascript拼接方法混乱

Question

Hey guys im working on a problem that searches the string and replaces x with y in my case before & after. But for some reason my splice() method is just returning the deleted element. and thats where im actually stuck at..... Take a look at my code below, thanks

    function replace(str, before, after) {
        /* logic 
      1. put the string into an array with split() 
      2. search array index and replace 2nd argument with 3rd argument 
      3. turn array back into string wtih join() method
      */
        // turn string into an array
        var strIntoArray = str.split(' ');

        // looping thru array
        for( i = 0; i < strIntoArray.length; i++){

            //compare index to arguments
            if (strIntoArray[i] === before) {
                // replace index with arguments with splice() method
                // this part is a lot more complex
                console.log(strIntoArray.splice(strIntoArray.indexOf(before), 1, after));

            }
        }

        //console.log(strIntoArray);
    }

replace("A quick brown fox jumped over the lazy dog", "jumped", "leaped");

Answer 1

That's how splice() works. It returns the removed element, but changes the original array. If you output strIntoArray, the change should be made.