prototype.js分析 Enumerable

JavaScript

inGroupsOf() 配列をグループ分けして、要素が足りない場合はオプションで埋める

<script>
Array.prototype._each = function(iterator){
	for(var i=0, l=this.length; i<l; i++){
		iterator(this[i]);
	}
};

Array.prototype.each = function(iterator){
	var index = 0;
	try{
		this._each(function(v){
			iterator(v, index++);
		});
	} catch(e){
		if(e != $break) throw e;
	}
};

Array.prototype.collect = function(iterator){
	var iterator = iterator || function(x){return x};
	var rs = [];
	this.each(function(v, k){
		rs.push(iterator(v, k));
	});
	return rs;
};

Array.prototype.eachSlice = function(number, iterator){
	var index = -number, slices = [], array = this.collect();
	while((index += number) < array.length)
		slices.push(array.slice(index, index + number));
	return slices.collect(iterator);
};

Array.prototype.inGroupsOf = function(number, fillWith){
	fillWith = (fillWith === undefined) ? null : fillWith;
	return this.eachSlice(number, function(slice){
		//console.log(slice);
		while(slice.length < number) slice.push(fillWith);
		return slice;
	});
};

var $break = {};
var kekka = "10,15,20,30,35".split(',').inGroupsOf(3, 'nanasi');
console.log(kekka);
</script>