Reputation: 35223
John Resig, creator of jQuery created a very handy Array.remove method that I always use it in my projects:
// Array Remove - By John Resig (MIT Licensed)
Array.prototype.remove = function(from, to) {
var rest = this.slice((to || from) + 1 || this.length);
this.length = from < 0 ? this.length + from : from;
return this.push.apply(this, rest);
};
// Remove the second item from the array
array.remove(1);
// Remove the second-to-last item from the array
array.remove(-2);
// Remove the second and third items from the array
array.remove(1,2);
// Remove the last and second-to-last items from the array
array.remove(-2,-1);
It works great. But I would like to know if it's extendable so that it can take an array of indexes as the first argument?
Otherwise, I will probably make another method that makes use of it:
if (!Array.prototype.removeIndexes) {
Array.prototype.removeIndexes = function (indexes) {
var arr = this;
if (!jQuery)
throw new ReferenceError('jQuery not loaded');
$.each(indexes, function (k, v) {
var index = $.inArray(v, indexes);
if (index !== -1)
arr.remove(index);
});
};
}
If Array.remove()
isn't extendable to fit my needs, what do you think about my other solution above?
Upvotes: 1
Views: 429
Reputation:
This version should work. It modifies the original array. If you prefer to return a new array without modifying the original, use the commented out initializer of result
and add return result
at the end of the function.
Array.prototype.removeIndexes = function(indices) {
// make sure to remove the largest index first
indices = indices.sort(function(l, r) { return r - l; });
// copy the original so it is not changed
// var result = Array.prototype.slice.call(this);
// modify the original array
var result = this;
$.each(indices, function(k, ix) {
result.splice(ix, 1);
});
}
> [0, 1, 2, 3, 4, 5, 6, 7, 8].removeIndexes([4, 5, 1]);
> [0, 2, 3, 6, 7, 8]
Upvotes: 1
Reputation: 8987
I think this is what you are looking for (It works with negative index too) :
if (!Array.prototype.removeIndexes) {
Array.prototype.removeIndexes = function (indexes) {
var arr = this;
if (!jQuery) throw new ReferenceError('jQuery not loaded');
var offset = 0;
for (var i = 0; i < indexes.length - 1; i++) {
if (indexes[i] < 0)
indexes[i] = arr.length + indexes[i];
if (indexes[i] < 0 || indexes[i] >= arr.length)
throw new Error('Index out of range');
}
indexes = indexes.sort();
for (var i = 0; i < indexes.length - 1; i++) {
if (indexes[i + 1] == indexes[i])
throw new Error('Duplicated indexes');
}
$.each(indexes, function (k, index) {
arr.splice(index - offset, 1);
offset++;
});
return arr;
};
}
var a = ['a', 'b', 'c', 'd', 'e', 'f'];
var ind = [3, 2, 4];
a.removeIndexes(ind);
console.log(a.join(', '));
// returns : a, b, f
Upvotes: 1
Reputation: 10880
How about
Array.prototype.remove = function (indexes) {
if(indexes.prototype.constructor.name == "Array") {
// your code to support indexes
} else {
// the regular code to remove single or multiple indexes
}
};
Upvotes: 0