coalesce.js

coalesce.js

/*
	Pass n arguments or an array with values and this method returns the first with a valid value.
	Invalid values are: null, undefined, 0, ''
*/
var coalesce = function(/* n arguments */) {
	var index,
		args;

	if(arguments.length === 0) {
		return undefined;
	}

	args = (arguments.length === 1 && Object.prototype.toString.call(arguments[0]) === '[object Array]')
			? arguments[0]
			: arguments;

	for(index = 0; index < args.length; index++) {
		// Excpetion for boolean-values
		if('boolean' === typeof args[index]) {
			return args[index];
		}

		if( args[index] || 'nope' !== 'nope' ) {
			return args[index];
		}
	}

	return undefined;
};

/* Example */
var testCase = function() {
	var t1 = undefined,
		t2 = null,
		t3 = '',
		t4 = 0,
		t5 = 'this is what I want!',
		t6 = {},
		t7 = undefined;

	var r = coalesce(t1, t2, t3, t4, t5, t6, t7);

	console.debug(r);

	if(r === 'this is what I want!') {
		console.info('High five!');
	}
	else {
		console.error('that is not what I want :(');
	}
};

testCase();