right = mid - 1;
else if (cmp > 0)
left = mid + 1;
else
return mid;
}
return -1;
}
/** Returns true if this array contains
* key; otherwise returns false. */
Array.prototype.contains = function(key, compare) {
return this.linearSearch(key, compare) != -1;
}
/** Adds all the elements in the
* specified arrays to this array. */
Array.prototype.addAll = function() {
for (var a = 0; a < arguments.length; a++) {
arr = arguments[a];
for (var i = 0; i < arr.length; i++) {
this.push(arr[i]);
}
}
}
/** Retains in this array all the elements
* that are also found in the specified array. */
Array.prototype.retainAll = function(arr, compare) {
if (typeof(compare) == "undefined") {
compare = simpleCompare;
}
for (var i = 0; i < this.length; i++) {
if (arr.contains(this[i], compare) == false) {
var end = i + 1;
while (end < this.length &&
arr.contains(this[end], compare) == false) {
end++;
}
this.splice(i, end - i);
}
else {
i++;
}
}
}
/** Removes from this array all the elements
* that are also found in the specified array. */
Array.prototype.removeAll = function(arr, compare) {
if (typeof(compare) == "undefined") {
compare = simpleCompare;
}
var i = 0;
while (i < this.length) {
if (arr.contains(this[i], compare)) {
var end = i + 1;
while (end < this.length &&
arr.contains(this[end], compare)) {
end++;
}
this.splice(i, end - i);
}
else {
i++;
}
}
}
/** Compares two objects using
* built-in JavaScript operators. */
function simpleCompare(a, b) {
if (a < b)
return -1;
else if (a > b)
return 1;
return 0;
}
Using the Six Missing Functions
To use the six functions, include the array.js file that you made in the head of an HTML file like this:
<script type="text/JavaScript" src="array.js"></script>
Then you can write JavaScript to use the functions similar to this:
<script type="text/JavaScript">
function test() {
document.open();
var setX = [ "apple", "pear", "plum", "peach" ];
document.writeln('setX: " + setX + "<br />');
var possible = "plum";
document.writeln('setX.contains(' + possible + ") " +
setX.contains(possible) + "<br />");
possible = "cherry";
document.writeln('setX.contains(' + possible + ") " +
setX.contains(possible) + "<br />");
var setW = [ "cherry", "banana", "apricot", "mango" ];
setX.addAll(setW);
setX.sort();
document.writeln('<br />');
document.writeln('setX: " + setX + "<br />');
possible = "peach";
if (setX.binarySearch(possible) != -1)
document.writeln('setX contains " + possible + "<br />');
else
document.writeln('setX does not contain " + possible + "<br />');
possible = "coconut";
if (setX.binarySearch(possible) != -1)
document.writeln('setX contains " + possible + "<br />');
else
document.writeln('setX does not contain " + possible + "<br />');
var setY = [ "elm", "pine", "rose", "lilac" ];
var setZ = [ "lilac", "pine", "fir" ];
document.writeln('<br />');
document.writeln('setY: " + setY + "<br/>');
document.writeln('setZ: " + setZ + "<br/>');
setX.addAll(setY, setZ);
document.writeln('setX.addAll(setY, setZ): " + setX + "<br />');
setY = [ "elm", "pine", "rose", "lilac" ];
setY.retainAll(setZ);
document.writeln('setY.retainAll(setZ): " + setY + "<br />');
setY = [ "elm", "pine", "rose", "lilac" ];
setY.removeAll(setZ);
document.writeln('setY.removeAll(setZ): " + setY + "<br />');
document.close();
}
</script>
