简单JS累加器

function Accumulator(){

    this.length = 0;
    this.average = 0;
    this.sum = 0;
    this.max = Number.NEGATIVE_INFINITY;  //无穷小
    this.min = Number.POSITIVE_INFINITY;  //无穷大
    this.add = function(val){
        this.length++;
        this.average = this.average + ( val - this.average ) / this.length;
        this.sum += val;
        if(val > this.max){
            this.max = val;
        }
        if(val < this.min){
            this.min = val;
        }
    }

}

每添加一个数字都会自动算出总数、平均值、最大、最小值、长度。

var accumulator = new Accumulator();
accumulator.add(16);
accumulator.add(32);
accumulator.add(64);
accumulator.sum;  //  112
accumulator.average; //  37.333333333333336
accumulator.max;  //  64
accumulator.min;  //  16
accumulator.length;  //  3