## 1.根据对象的属性值排序

function createComparisonFunction(propertyName){
  return function(object1,object2){
     var value1 =  object1[propertyName];
     var value2 =  object2[propertyName];

     if(value1 < value2){
        return -1;
     }else if(value1 > value2){
       return 1;
     }else{
       return 0;
     }
  };
}