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 or undefined. Instead, the function returns false.

    var bool = hasOwnProp( null, 'a' );
    // returns false
    
    bool = hasOwnProp( void 0, 'a' );
    // returns false
    
  • Value arguments other than null or undefined are coerced to objects.

    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