deepHasProp

Test whether an object contains a nested key path, either own or inherited.

Usage

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

deepHasProp( value, path[, options] )

Returns a boolean indicating if a value has a specified path, either own or inherited.

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

var obj = { 'a': new Foo() };

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

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

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

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

deepHasProp.factory( path[, options] )

Returns a function which tests whether a value contains a nested key path, either own or inherited.

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

has( value )

Returns a boolean indicating whether a value contains a nested key path, either own or inherited.

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

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

var obj = { 'a': new Foo() };

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

Notes

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

    var bool = deepHasProp( null, 'a.b.c' );
    // returns false
    
    bool = deepHasProp( void 0, 'a.b.c' );
    // returns false
    
  • Property values other than null or undefined are coerced to objects.

    var obj = {
        'a': 'b'
    };
    
    var bool = deepHasProp( obj, 'a.length' );
    // returns true
    
  • Key path array elements are coerced to strings.

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

Examples

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

var bool;
var has;

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

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

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

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

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

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

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

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

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