Decrement¶

Description¶

This operation decrements the value of the specified key by a specific number.

Method¶

Objective-CSwift

[[[Backendless.shared hive:(NSString *)hiveName] mapStore:(NSString *)keyName] decrementWithKey:(NSString *)key count:(NSInteger)count responseHandler:^(NSInteger)responseHandler errorHandler:^(Fault *)errorHandler];

Backendless.shared.hive(hiveName: String).mapStore(keyName: String).decrement(key: String, count: Int, responseHandler: ((Int) -> Void)!, errorHandler: ((Fault) -> Void)!)

where:

Argument	Description
`hiveName`	Name of a hive where the operation is performed. String value.
`keyName`	Key name identifying a map. String value.
`key`	Key name identifying a key-value pair. String value.
`count`	Specify the number to decrement the value of the specified key.

Return Value¶

The decremented value.

Examples¶

Decrement The Value By n - 1

The example below decrements the value of the "Apples" key by 1. When this operation is used without the count parameter, then the value is always decremented by 1 for every query made.

Objective-CSwift

[[[Backendless.shared hive:@"groceryStore"] mapStore:@"fruits"] decrementWithKey:@"Apples" responseHandler:^(NSInteger response) {
    // handle response
} errorHandler:^(Fault *fault) {
    // handle error
}];

Backendless.shared.hive("groceryStore").mapStore("fruits").decrement(key: "Apples", responseHandler: { response in
    // handle response
}, errorHandler: { fault in
    // handle error
})

where:

Argument	Description
`"groceryStore"`	Name of a hive where the operation is performed.
`"fruits"`	Key name identifying a map.

Decrement The Value By A Number

The example below decrements the value of the "Apples" key by 3.

Objective-CSwift

[[[Backendless.shared hive:@"groceryStore"] mapStore:@"fruits"] decrementWithKey:@"Apples" count:3 responseHandler:^(NSInteger response) {
    // handle response
} errorHandler:^(Fault *fault) {
    // handle error
}];

Backendless.shared.hive("groceryStore").mapStore("fruits").decrement(key: "Apples", count: 3, responseHandler: { response in
    // handle response
}, errorHandler: { fault in
    // handle error
})

where:

Argument	Description
`"groceryStore"`	Name of a hive where the operation is performed.
`"fruits"`	Key name identifying a map.

Codeless Reference¶

map_api_decrement

where:

Argument	Description
`hive name`	Name of a hive where the operation is performed.
`key name`	Key name identifying a map.
`object key name`	Key name identifying a key-value pair.
`decrement by`	Specify the number to decrement the value of the specified key.

Returns the decremented value.

Consider the following Map storage:
map_apI_example_map_store_6

The example below decrements the value of the key "Apples" by 3.

map_api_example_decrement

The map will look as shown below after the Codeless logic runs:
map_apI_example_map_store_8