Confirming the Ending

1

Hi,
I’ve been working on “Confirming the Ending” challenge in basic algorithm scripting section.
I was able to write it on my own and achieved the desired result. In the challenge, it was given to use ‘String.prototype.substr()’ as helpful links. But I did not use it and I was able to achieve the final output with what I’ve learned so far. I haven’t come across substrings as far as I remember.
So, I’d like to know your comments and improvements to the code.

Thanks for any help.

Here is my code:
>> function confirmEnding(str, target) {

          // "Never give up and good luck will find you."
          // -- Falcor
          var splitStr=str.split(" ");
          //return splitStr.length;
          if(splitStr.length>1){
             var lastWord=splitStr[splitStr.length-1];

         if(lastWord.indexOf(target)>-1){
        return true;
      }
      else return false;
     }
      else{
        var singleWord=splitStr.join('').split("");
      var lastLetter=singleWord[singleWord.length-1];
        
        if(lastLetter==target){
          return true;
        }
       else return false;
      }

      //return splitStr;
    }

    confirmEnding("Open sesame", "same");
2

This can be reduced to one line of code.

HINT: Investigate, read the docs on substr() with negative arguments in the parenthesis.

3

im rather new as well…i can show you what i did. i guess javascript is cool because our ways look different but both work.

function confirmEnding(str, target) {
 let a = target.length;
 let b = str.length;
 let c = str.slice(b-a);
if(c===target){return true;}
else{return false;}

}

string prototype has so many methods its crazy

4 
function confirmEnding(str, target) {
return(str.slice(str.length-target.length)===target) ? true : false;}

we can reduce things down with ternary operator syntax
this is how mine would look

right now ternary style is tougher for me to look at i like piece by piece, but i guess i see the benefit in the long run of typing less code

5

wow… thanks, Benjaminadk. It indeed shrinked to two lines. I should practice a lot not to use if/else statements all the time. :slight_smile:
I hope you did not use the word ‘let’ in your code. :wink: But the slice takes two arguments, isn’t it? You’ve written slice(b-a)?

@owel - thank you. still learning all the concepts of string manipulations. I hope one day I will write light weight code like you guys. :slight_smile:

6

yah slice can take one or two arguments. b-a is actually one argument though. js will do that math first then do slice. just like math parenthesis first. slice(a,b) would be start at a and end at b and whats in between gets returned

7

Another solution.
(Click to unblur.)

function confirmEnding(str, target) {
    return (str.substr(-target.length) == target);
}
8

I went down a different (maybe slightly cheaty) route. Regex seemed like a better fit for checking a string ending. But adding a variable to regex was a struggle till I saw this on Stack Overflow.


ble-inside-a-regular-expression

So my solution using this method was…

function confirmEnding(str, target) {
  let stringCheck = new RegExp(target + '$', "i");
  return stringCheck.test(str);
}