2.8 KiB
2.8 KiB
hasOwnProperty
Test if an object has a specified property.
Usage
var hasOwnProp = require( '@stdlib/assert/has-own-property' );
hasOwnProp( value, property )
Returns a boolean
indicating if a value
has a specified property
.
var value = {
'beep': 'boop'
};
var bool = hasOwnProp( value, 'beep' );
// returns true
bool = hasOwnProp( value, 'bap' );
// returns false
Notes
-
In contrast to the native Object.prototype.hasOwnProperty, this function does not throw when provided
null
orundefined
. Instead, the function returnsfalse
.var bool = hasOwnProp( null, 'a' ); // returns false bool = hasOwnProp( void 0, 'a' ); // returns false
-
Value arguments other than
null
orundefined
are coerced toobjects
.var bool = hasOwnProp( 'beep', 'length' ); // returns true
-
Property arguments are coerced to
strings
.var value = { 'null': false }; var bool = hasOwnProp( value, null ); // returns true value = { '[object Object]': false }; bool = hasOwnProp( value, {} ); // returns true
Examples
var hasOwnProp = require( '@stdlib/assert/has-own-property' );
var bool = hasOwnProp( { 'a': 'b' }, 'a' );
// returns true
bool = hasOwnProp( { 'a': 'b' }, 'c' );
// returns false
bool = hasOwnProp( { 'a': 'b' }, null );
// returns false
bool = hasOwnProp( {}, 'hasOwnProperty' );
// returns false
bool = hasOwnProp( null, 'a' );
// returns false
bool = hasOwnProp( void 0, 'a' );
// returns false
bool = hasOwnProp( { 'null': false }, null );
// returns true
bool = hasOwnProp( { '[object Object]': false }, {} );
// returns true