deepHasOwnProp

Test whether an object contains a nested key path.

Usage

var deepHasOwnProp = require( '@stdlib/assert/deep-has-own-property' );

deepHasOwnProp( value, path[, options] )

Returns a boolean indicating if a value has a specified path.

var obj = { 'a': { 'b': { 'c': 'd' } } };

var bool = deepHasOwnProp( obj, 'a.b.c' );
// returns true

bool = deepHasOwnProp( obj, 'a.b.c.d.e' );
// returns false

If a key path includes an array, specify the numeric index.

var arr = [
    {
        'a': [
            {
                'b': [
                    { 'c': 'd' },
                    { 'e': 'f' }
                ]
            }
        ]
    }
];

var bool = deepHasOwnProp( arr, '0.a.0.b.0.c' );
// returns true

bool = deepHasOwnProp( arr, '0.a.1.b.0.c' );
// returns false

bool = deepHasOwnProp( arr, '0.a.0.b.1.c' );
// returns false

The key path may be specified as either a delimited string or a key array.

var obj = { 'a': { 'b': { 'c': 'd' } } };

var bool = deepHasOwnProp( obj, [ 'a', 'b', 'c' ] );
// returns true

The function accepts the following options:

sep: key path separator. Default: '.'.

By default, the function assumes . separated key values. To specify an alternative separator, set the sep option.

var obj = { 'a': { 'b': { 'c': 'd' } } };

var bool = deepHasOwnProp( obj, 'a/b/c', {
    'sep': '/'
});
// returns true

deepHasOwnProp.factory( path[, options] )

Returns a function which tests whether a value contains a nested key path.

var has = deepHasOwnProp.factory( 'a/b/c', {
    'sep': '/'
});

has( value )

Returns a boolean indicating whether a value contains a nested key path.

var has = deepHasOwnProp.factory( 'a.b.c' );

var obj = { 'a': { 'b': { 'c': 'd' } } };

var bool = has( obj );
// returns true

Notes

Only own properties are tested. Paths matching inherited properties are not considered.

function Foo() {
    this.a = 'b';
    return this;
}
Foo.prototype.c = 'd';

var foo = new Foo();

var bool = deepHasOwnProp( foo, 'a' );
// returns true

bool = deepHasOwnProp( foo, 'c' );
// returns false

When provided null or undefined, the function result is always false.

var bool = deepHasOwnProp( null, 'a.b.c' );
// returns false

bool = deepHasOwnProp( void 0, 'a.b.c' );
// returns false

Property values other than null or undefined are coerced to objects.

var obj = {
    'a': 'b'
};

var bool = deepHasOwnProp( obj, 'a.length' );
// returns true

Key path array elements are coerced to strings.

var obj = {
    'null': false
};
var bool = deepHasOwnProp( obj, [ null ] );
// returns true

obj = {
    '[object Object]': false
};
bool = deepHasOwnProp( obj, [ {} ] );
// returns true

Examples

var deepHasOwnProp = require( '@stdlib/assert/deep-has-own-property' );

var bool = deepHasOwnProp( { 'a': { 'b': { 'c': 'd' } } }, 'a.b.c' );
// returns true

bool = deepHasOwnProp( { 'a': { 'b': { 'c': 'd' } } }, [ 'a', 'b', 'c' ] );
// returns true

bool = deepHasOwnProp( { 'a': { 'b': { 'c': 'd' } } }, 'a/b/c', {
    'sep': '/'
});
// returns true

bool = deepHasOwnProp( { 'a': { 'b': { 'c': 'd' } } }, 'a.b.c.d' );
// returns false

bool = deepHasOwnProp( { 'a': [ { 'b': { 'c': 'd' } } ] }, [ 'a', '0', 'b', 'c', 'd' ] );
// returns false

bool = deepHasOwnProp( { 'a': { 'b': { 'c': 'd' } } }, 'a/b/c/d/e', {
    'sep': '/'
});
// returns false

// Create a customized function:
var has = deepHasOwnProp.factory( 'a_b_c', {
    'sep': '_'
});

bool = has( { 'a': { 'b': { 'c': 'd' } } } );
// returns true

bool = has( { 'a': [ { 'b': { 'c': 'd' } } ] } );
// returns false