Validating File Extensions with JavaScript

FileExtension.js

        /**
         * Checks through       a list of fileURI's and compares the
         * file extensions      of those fileURI's to the acceptedPhotoTypes
         * @param files         array of objects with a source property, this property is the fileURI location of the photo
         * @param acceptedTypes an array of accepted photo types. EG '.jpeg'
         * @returns {boolean}
         */
        function validateFileExtensions(files, acceptedTypes) {
            var passed = false;

            /**
             * Checks a single file URI for the existance of  a
             * accepted file extension
             * @param fileUri
             * @returns {boolean}
             */
            function checkFileUri(fileUri) {
                for (var i = 0; i < acceptedTypes.length; i++) {
                    if (fileUri.indexOf(acceptedTypes[i]) > -1) {
                        passed = true
                    }
                }
                return passed;
            }

            for (var i = 0; i < files.length; i++) {
                passed = checkFileUri(files[i].source);
            }

            return passed;
        }