jsdatastructures/Set.html at master · mrmabo/jsdatastructures · GitHub

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<script>
function Set() {
    this.dataStore = [];
}

Set.prototype = {
    add: function(data) {
        // 数组的push()方法 插入元素会返回 Number——1 再利用 !!() 转化为Boolean——true
        return this.contains(data) === false ? !!(this.dataStore.push(data)) : false;
    },
    remove: function(data) {
        var index = this.contains(data, true);
        index = isNaN(index.toString()) ? this.size() : index;
        // 数组的splice()方法 会返回一个数组(空或非空) 要将其正确转换为Boolean就需要用join('')将空数组转换为空字符串
        // contains(data, true) 返回index或者false 整体为两类 但是index为0这种情况要作为正确的处理就需要用isNaN()来将结果判断 isNaN('false')是true isNaN(0)是false
        // 还有个相关的技巧 0 +/- Boolean 将Boolean转化为Number
        return !!(this.dataStore.splice(index, 1).join(''));
    },
    show: function() {
        var i=0,
            len = this.dataStore.length;
        while(i < len) {
            document.writeln("</br>")
            document.writeln(this.dataStore[i]);
            i++;
        }
    },
    size: function() {
        return this.dataStore.length;
    },

    contains: function(data, getIndexSign) {
        var index = this.dataStore.indexOf(data);
        return index > -1 ? getIndexSign === true ? index : true : false;
    },
    repeat: function (set, conditionSign) {
        var tempSet = new Set(),
            i = 0,
            len = this.size(),
            thisCurDataStore = null;
        for(i = 0; i < len; i++) {
            thisCurDataStore = this.dataStore[ i ];
            if ((conditionSign && set.contains(thisCurDataStore)) || (!conditionSign && !set.contains(thisCurDataStore))) {
                tempSet.dataStore.push(thisCurDataStore);
            }
        }
        return tempSet;
    },
    union: function(set) {
        var tempSet = new Set(),
            dataStore = this.dataStore,
            i = 0,
            len = dataStore.length,
            setCurDataStore = null;

        // 拷贝当前集合中的元素到临时集合temp
        for (i = 0; i < len; i++) {
            tempSet.dataStore.push(dataStore[ i ]);
        }

        // 进行集合的并集
        for(i = 0, len = set.size(); i < len; i++) {

            setCurDataStore = set.dataStore[ i ];

            if (!tempSet.contains(setCurDataStore)) {
                tempSet.dataStore.push(setCurDataStore);
            }
        }

        return tempSet;
    },
    subset: function(set) {
        var that = this;
        if (this.size() > set.size()) {
            // 利用ECMAScript5中数组新增的every()方法
            return set.dataStore.every(function (item) {
                return that.contains(item);
            });
        }
        else {
            return false;
        }
    },
    difference: function(set) {
        return this.repeat.apply(this, [set, false]);
    },
    intersect : function(set) {
        return this.repeat.apply(this, [set, true]);
    }

}
var set = new Set(),
    set2 = new Set();
document.writeln('测试add: ');
document.writeln(set.add('aaa'));
document.writeln(set.add('aaa'));
document.writeln(set.add('bbb'));
document.writeln(set.add('qqq'));
document.writeln(set.add('www'));
document.writeln(set.add('eee'));

document.writeln(set2.add('qqq'));
document.writeln(set2.add('www'));
document.writeln(set2.add('eee'));

document.writeln('</br>')
document.writeln('测试show: ');
set.show();
document.writeln('</br>')
document.writeln('测试remove: ');
document.writeln(set.remove('aaa'));
document.writeln(set.remove('zzz'));
document.writeln('</br>')
document.writeln('测试show: ');
set.show()
document.writeln('</br>')
document.writeln('测试union: ');
set.union(set2).show()
document.writeln('</br>')
document.writeln('测试intersect: ');
set.intersect(set2).show()
document.writeln('</br>')
document.writeln('测试subset: ');
document.writeln(set.subset(set2));
document.writeln('</br>')
document.writeln('测试difference: ');
set.difference(set2).show()
</script>