用js数组求和、最大值、最小值、平均值简便写法

/*平均值：*/  [1,2,3,4,5,6,7,8,9,10].reduce((a,b,c)=>(a*c+b)/(c+1))
/*最大值：*/  [1,2,3,4,5,6,7,8,9,10].reduce((a,b)=>(a>b?a:b))
/*最小值  */  [1,2,3,4,5,6,7,8,9,10].reduce((a,b)=>(a<b?a:b))
/*求和 */     [1,2,3,4,5,6,7,8,9,10].reduce((a,b)=>a+b)

注意：Array的reduce方法需要es5支持,如果浏览器不支持可以使用以下shim

if (typeof Array.prototype.reduce != "function") {
  Array.prototype.reduce = function (callback, initialValue ) {
     var previous = initialValue, k = 0, length = this.length;
     if (typeof initialValue === "undefined") {
        previous = this[0];
        k = 1;
     }
     
    if (typeof callback === "function") {
      for (k; k < length; k++) {
         this.hasOwnProperty(k) && (previous = callback(previous, this[k], k, this));
      }
    }
    return previous;
  };
}