Javascript 自定义排序函数

Question

我有一个定义如下的自定义排序函数

sortArrayBy: function(a, b, sortKey) {
    if (a[sortKey] < b[sortKey])
        return -1;
    if (a[sortKey] > b[sortKey])
        return 1;
    return 0;
},

我如何更新它以根据附加参数 isAscending 动态排序/切换，它可以是 true/false

所以函数签名看起来像

sortArrayBy: function(a, b, sortKey, isAscending) {

}

Answer 1

将 isAscending 转换为 1(升序)或 -1(降序)

sortArrayBy: function(a, b, sortKey, isAscending) {
   return (a[sortKey] - b[sortKey]) * (isAscending ? 1 : -1);
}

演示

function sortArrayBy(arr, sortKey, isAscending) {
  return arr.sort( ( a, b ) => (a[sortKey] - b[sortKey]) * (isAscending ? 1 : -1) );
}

var arr = [
   { a : 1, b: 2 },
   { a : 4, b: 6 },
   { a : 3, b: 4 },
   { a : 12, b: 1 },
   { a : 5, b: 23 },
];

console.log( sortArrayBy( arr, "a", true ) );

console.log( sortArrayBy( arr, "a", false ) );

编辑

也包括字符串比较

function sortArrayBy(arr, type, sortKey, isAscending) {
  if ( type == "string" )
  {
     return arr.sort( ( a, b ) => a[sortKey].localeCompare(b[sortKey]) * (isAscending ? 1 : -1) );
  }

  return arr.sort( ( a, b ) => (a[sortKey] - b[sortKey]) * (isAscending ? 1 : -1) );
}

function sortArrayBy(arr, type, sortKey, isAscending) {
  if ( type == "string" )
  {
     return arr.sort( ( a, b ) => a[sortKey].localeCompare(b[sortKey]) * (isAscending ? 1 : -1) );
  }
  
  return arr.sort( ( a, b ) => (a[sortKey] - b[sortKey]) * (isAscending ? 1 : -1) );
}

var arr = [
   { a : 1, b: "32" },
   { a : 4, b: "w6" },
   { a : 3, b: "s4" },
   { a : 12, b: "v1" },
   { a : 5, b: "2s3" },
];

console.log( sortArrayBy( arr, "", "a", true ) );

console.log( sortArrayBy( arr, "", "a", false ) );


console.log( sortArrayBy( arr, "string", "b", true ) );

console.log( sortArrayBy( arr, "string", "b", false ) );