# isNonConfigurableProperty > Test if an object's own property is non-configurable.
## Usage ```javascript var isNonConfigurableProperty = require( '@stdlib/assert/is-nonconfigurable-property' ); ``` #### isNonConfigurableProperty( value, property ) Returns a `boolean` indicating if a `value` has a non-configurable `property` (i.e., a property which cannot be deleted and whose descriptor cannot be changed). ```javascript var defineProperty = require( '@stdlib/utils/define-property' ); var obj = { 'foo': 'bar' }; defineProperty( obj, 'beep', { 'configurable': false, 'enumerable': true, 'writable': true, 'value': 'boop' }); var bool = isNonConfigurableProperty( obj, 'beep' ); // returns true bool = isNonConfigurableProperty( obj, 'foo' ); // returns false ```
## Notes - Value arguments other than `null` or `undefined` are coerced to `objects`. ```javascript var bool = isNonConfigurableProperty( 'beep', 'length' ); // returns true ```
## Examples ```javascript var isNonConfigurableProperty = require( '@stdlib/assert/is-nonconfigurable-property' ); var bool = isNonConfigurableProperty( [ 'a' ], 'length' ); // returns true bool = isNonConfigurableProperty( { 'a': 'b' }, 'a' ); // returns false bool = isNonConfigurableProperty( [ 'a' ], 0 ); // returns false bool = isNonConfigurableProperty( {}, 'toString' ); // returns false bool = isNonConfigurableProperty( {}, 'hasOwnProperty' ); // returns false bool = isNonConfigurableProperty( null, 'a' ); // returns false bool = isNonConfigurableProperty( void 0, 'a' ); // returns false bool = isNonConfigurableProperty( { 'null': false }, null ); // returns false bool = isNonConfigurableProperty( { '[object Object]': false }, {} ); // returns false ```