IDBKeyRange.includes()
The includes()
method of the IDBKeyRange
interface returns a boolean indicating whether a specified key is inside the key
range.
Note: This feature is available in Web Workers
Syntax
includes(key)
Parameters
key
-
The key you want to check for in your key range. This can be any type.
Return value
A boolean value.
Exceptions
DataError
DOMException
-
Thrown if the supplied key was not a valid key.
Examples
var keyRangeValue = IDBKeyRange.bound('A', 'K', false, false);
var myResult = keyRangeValue.includes('F');
// Returns true
var myResult = keyRangeValue.includes('W');
// Returns false
Polyfill
The includes()
method was added in the second edition of the Indexed DB
specification. For browsers that do not support it, the following polyfill can be used.
IDBKeyRange.prototype.includes = IDBKeyRange.prototype.includes || function(key) {
var r = this, c;
if (r.lower !== undefined) {
c = indexedDB.cmp(key, r.lower);
if (r.lowerOpen && c <= 0) return false;
if (!r.lowerOpen && c < 0) return false;
}
if (r.upper !== undefined) {
c = indexedDB.cmp(key, r.upper);
if (r.upperOpen && c >= 0) return false;
if (!r.upperOpen && c > 0) return false;
}
return true;
};
Specifications
Specification |
---|
Indexed Database API 3.0 # ref-for-dom-idbkeyrange-includes① |
Browser compatibility
BCD tables only load in the browser
See also
- Using IndexedDB
- Starting transactions:
IDBDatabase
- Using transactions:
IDBTransaction
- Setting a range of keys:
IDBKeyRange
- Retrieving and making changes to your data:
IDBObjectStore
- Using cursors:
IDBCursor
- Reference example: To-do Notifications (view example live.)