join.html

<script src="../simpletest.js"></script>
<script>

/* Prototype function
    function join(originalArray,optionalSeparator) {
        string returnString = '';
        for(var i = 0; i < originalArray.length; i++) {
            returnString += currentArray[i];
        }
        return returnString;
    }
*/

function join(originalArray,optionalSeparator) {
        var returnString = '';
        var separator = ',';
        var arrayLength = originalArray.length;
        if(1 in arguments) separator = optionalSeparator;
        for(var i = 0; i < arrayLength; i++) {
            returnString += originalArray[i];
            if(i < (arrayLength - 1)) returnString += separator;
        }
        return returnString;
    }


tests({

  'It should return a string': function () {
    var result = join([1,2,3]);
    eq(typeof result === 'string',true);
  },

  'It should accept a separator': function () {
    var result = join([1,2,3],'-');
    eq(result === '1-2-3',true);
  },

  'It should use a comma as the default separator if none provided': function () {
    var result = join([1,2,3]);
    eq(result === '1,2,3',true);
  },

  'It should accept an empty string as a separator': function() {
    var result = join([1,2,3],'');
    eq(result === '123',true);
  },

  'It should convert a separator to a string': function() {
    var result = join([1,2,3],4);
    eq(result === '14243',true);
  },

  'It should not modify the original array': function () {
    var testArray = [1,2,3];
    var testCopy = [1,2,3];
    join(testArray);
    eq(testArray.length,testCopy.length);
    for(var i = 0; i < testCopy.length; i++){
        eq(testArray[i],testCopy[i]);
    } 
  },

});

</script>