# omitBy > Return a partial object copy excluding properties for which a predicate (function) returns a truthy value.
## Usage ```javascript var omitBy = require( '@stdlib/utils/omit-by' ); ``` #### omitBy( obj, predicate ) Returns a partial object copy excluding properties for which a `predicate` returns a truthy value. ```javascript function predicate( key, value ) { return ( value > 1 ); } var obj1 = { 'a': 1, 'b': 2, 'c': 3 }; var obj2 = omitBy( obj1, predicate ); // returns { 'a': 1 } ```
## Notes - The function returns a **shallow** copy. - The function **only** copies **own** properties. Hence, the function never copies inherited properties.
## Examples ```javascript var omitBy = require( '@stdlib/utils/omit-by' ); function predicate( key, value ) { return ( typeof value === 'number' ); } var obj1 = { 'a': '1', 'b': 2, 'c': NaN, 'd': null }; var obj2 = omitBy( obj1, predicate ); // returns { 'a': '1', 'd': null } ```