function enum2str( dtype ) {
	var v = hash[ dtype ];
	return ( typeof v === 'string' ) ? v : null; // note: we include this guard to prevent walking the prototype chain
}
Returns the data type string associated with an ndarray data type enumeration constant.

@param {integer} dtype - data type enumeration constant
@returns {(string|null)} data type string or null

@example
var str2enum = require( '@stdlib/ndarray/base/dtype-str2enum' );

var v = str2enum( 'float64' );
// returns <number>

var dt = enum2str( v );
// returns 'float64'