Function compareFields

compareFields<ObjectType>(
...fields: FieldSpec<ObjectType>[],
): Comparator<ObjectType>
Creates a new comparator function that compares the fields of its input arguments using the given specification. The function can then be used, for example, in calls to Array.sort().
Type Parameters
- ObjectType
Parameters
- ...fields: FieldSpec<ObjectType>[]
  A list of fields that specify the object comparison. This can be a direct field name or an object specifier for advanced configuration. Multiple field names or objects are also supported, in which case the new comparator will create a lexicographic order based on these fields.
  
  A field name is considered to be a string for member attributes, or a number to indicate a particular index of an array within the array to be sorted.
  
  The default comparison function compares fields using the builtin < and > operators, but a custom compare function can be specified when using the object notation.
  
  The order returned by the comparator is ascending by default.
Returns Comparator<ObjectType>
the new comparator function.
Example: _Sort by age, then by name_
```
const data = [
  { name: "B", age: 21 },
  { name: "A", age: 21 },
  { name: "C", age: 20 }
];
// Orders by age, or if ages are equal, by name.
data.sort(compareFields("age", "name"));
```
Example: _Reverse sort order for a single field_
```
const data = [
  { name: "B", age: 21 },
  { name: "A", age: 21 },
  { name: "C", age: 20 }
];
data.sort(compareFields({ field: "age", reverse: true }, "name"));
```
Example: _Compare array items using indices as field "names"_
```
const data = [
  [1, 2],
  [1, 3],
  [2, 3],
];
// Orders by array item at index 1, or by index 0 if the other values are equal.
data.sort(compareFields(1, 0));
```
Example: _Compare field values with a custom comparator_
```
const compare = (a, b) => b - a; // Some custom comparison logic
const data = [
  { value: 3 },
  { value: 4 },
];
// Compares value using the custom comparison function
data.sort(compareFields({ field: "value", compare: compare }));
```
Example: _Compare field values with a custom value picker_
```
const valuePicker = (a) => a.value ?? 0; // Some custom value lookup logic, e.g. default values
const data = [
  { value: 3 },
  { value: 4 },
];
// Compares value using the custom comparison function
data.sort(compareFields({ valuePicker }));
```
- Defined in comparators.ts:344

Function compareFields

Type Parameters

Parameters

Returns Comparator<ObjectType>

Example: _Sort by age, then by name_

Example: _Reverse sort order for a single field_

Example: _Compare array items using indices as field "names"_

Example: _Compare field values with a custom comparator_

Example: _Compare field values with a custom value picker_

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