sharedCache.checkValueExists¶
Signature: sharedCache.checkValueExists(key, namespace*, global*, persist*)
Returns: Boolean exists - true if a value is found, false if a value is not found
Check for the existence of a Shared Cache value associated with the key, a result of true means the key was found.
When no namespace is specified, only keys set in the current channel are searched. When a namespace is specified, all channels in the same zone as the channel in which the key was set are searched. When global is set to true, all channels across all zones are searched.
Parameters¶
| Type | Name | Description | Default |
|---|---|---|---|
| String | key | a unique string used to identify the cached value | |
| String | namespace* | (optional) a unique string used to limit the scope of the search | Channel ID |
| Boolean | global* | (optional) specifies whether or not the key is searched for in the global cache | false |
| Boolean | persist* | (optional) specifies whether or not the key is stored in the database | false |
Example¶
// Example: Check whether a value exists in the shared cache.
// Define a cache key and store a value
var myKey = "this is the key";
sharedCache.setValue(myKey, "The secret lies with Charlotte.");
// Check if the key exists before retrieving the value
var exists = sharedCache.checkValueExists(myKey); // true
if (exists) {
var cachedValue = sharedCache.getValue(myKey); // "The secret lies with Charlotte."
}