element with that id
+ var compareDiv = document.getElementById(cardToCompare);
+ // 3. now drill down to the ![]()
inside that div
+ var compareImg = compareDiv.firstChild;
+ // (you could do the above in fewer steps, but I'm breaking it down for clarity)
+
+ // Is it a match?
+ // ie, is the comparison image the same as the current one?
+ if (compareImg.src == currentImg.src){
+ // add 1 to the count of matches
+ numMatches++;
+
+ // was this the final match?
+ if (numMatches == numCards/2){
+ alert("Finished! Good job!");
+ } else {
+ alert("Match!");
+ }
+
+ // set opacity on both matched cards
+ this.style.opacity = "0.5";
+ compareDiv.style.opacity = "0.5";
+
+ // reset the array of face-up cards
+ faceUpCards = [];
+ return; // got a match, so exit the function here
+ }
+ }
+ // add the id (ex: "card3") to the array of faced-up cards
+ faceUpCards.push(this.id);
+
+ } else { // if this image is showing, hide it
+ currentImg.style.display = "none";
+ // remove if from the array of face up cards
+ var indexNum = faceUpCards.indexOf(this.id);
+ faceUpCards.splice(indexNum,1);
+ // for more about these functions, see:
+ // http://www.w3schools.com/jsref/jsref_indexof_array.asp
+ // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice
+ }
+ console.log(faceUpCards);
+}
+
+
+/**
+ * Javascript doesn't have a built-in array shuffle function.
+ * This one is borrowed from:
+ * http://stackoverflow.com/questions/2450954/how-to-randomize-shuffle-a-javascript-array
+ */
+function shuffle(array) {
+ for (var i = array.length - 1; i > 0; i--) {
+ var j = Math.floor(Math.random() * (i + 1));
+ var temp = array[i];
+ array[i] = array[j];
+ array[j] = temp;
+ }
+}
\ No newline at end of file