javascript speed test

Aside

given the following function:

  function addInts(anArray){
     var result = 0;
     for (var i = 0; i < anArray.length; ++i){
        if (anArray[i] < 21) {
           result = result + anArray[i];
        } else { 
           result = result + anArray[i] - 21;
        }
     }
     return result;
  }

what would you expect will run faster?

    addInts(sortedArray); #sorted
    addInts(unsortedArray); #unsorted

 


 
check your answer


 

[More programming riddles]

javascript anagram detector

Aside

what’s the shortest anagram detector you know how to write, in javascript?


there must be a shorter way to do this. highlight below to see a solution.


var anagramDetector = function (x,y) {
   if (x.length != y.length) return false;
   var alpha_x = x.split("").sort().join("");
   var alpha_y = y.split("").sort().join("");
   for ( j = 0; j<y.length;++j) {
       if (alpha_x[j] != alpha_y[j]) return false;
  }
  return true;
}

PS: there’s a cool method for solving this for a fixed alphabet, using primes


[More programming riddles]

detecting anagrams in python

Aside

what’s the shortest anagram detector you know how to write, in python?


this is one that keeps feeling like it should be a one liner (because it’s very similar to this one liner), but i suspect can’t be done in one line

highlight to see a solution.


def fn(x,y):
    if len(x) != len(y):
        return False
    for i in x:
        y = y.replace(i,'',1)
    return not len(y) > 0

PS: there’s a cool method for solving this for a fixed alphabet, using primes


[More programming riddles]

javascript speed test

Aside

if you had to guess, which of the following two bits of javascript code would you say executes faster?

Exhibit A:

var keys = Object.keys(MyObj); //cloning the key array
var length = keys.length;
for (var i = 0; i < length; i++) {
  var val = MyObj[keys[i]];
};

Exhibit B:

for (var key in MyObj) {
 if (MyObj.hasOwnProperty(key)) { //hasOwnProperty is a native function
  var val = MyObj[key];
 }
}

Check your answer.


[More programming riddles]

 

 

 


this is what things looked like last year in september, with an up to date version of chrome:

Screen Shot 2013-09-17 at 7.04.32 PM