IDBFactory.cmp()

The cmp() method of the IDBFactory interface compares two values as keys to determine equality and ordering for IndexedDB operations, such as storing and iterating.

Note: This feature is available in Web Workers.

Note: Do not use this method for comparing arbitrary JavaScript values, because many JavaScript values are either not valid IndexedDB keys (booleans and objects, for example) or are treated as equivalent IndexedDB keys (for example, since IndexedDB ignores arrays with non-numeric properties and treats them as empty arrays, so any non-numeric arrays are treated as equivalent). This throws an exception if either of the values is not a valid key.

Syntax

var result = window.indexedDB.cmp(a, b);

Returns

An integer that indicates the result of the comparison; the table below lists the possible values and their meanings:

Returned value	Description
-1	1st key is less than the 2nd key
0	1st key is equal to the 2nd key
1	1st key is greater than the 2nd key

Exceptions

This method may raise a DOMException of the following types:

Attribute	Description
`DataError`	One of the supplied keys was not a valid key.

Example

var a = 1;
var b = 2;
var result = window.indexedDB.cmp(a, b);
console.log( "Comparison results: " + result );

Parameters

first: The first key to compare.
second: The second key to compare.

Specifications

Specification	Status	Comment
Indexed Database API The definition of 'cmp' in that specification.	Recommendation

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	23webkit 24	10 moz 16.0 (16.0)	10, partial	15	7.1
Available in workers	(Yes)	37.0 (37.0)	(Yes)	(Yes)	10

Feature	Android	Firefox Mobile (Gecko)	Firefox OS	IE Phone	Opera Mobile	Safari Mobile
Basic support	4.4	22.0 (22.0)	1.0.1	10	22	8
Available in workers	(Yes)	37.0 (37.0)	(Yes)	(Yes)	(Yes)	10