Voilà is the French-derived interjection meaning, literally, look there. In English, it’s often used to call attention to a novel result or to something just completed.
English speakers often pronounce the word wallah, resulting in various misspellings—including walla, wallah, wa la, and wa-la. It’s also commonly written without the grave accent above the a. This is not a serious spelling error, though, as English speakers typically drop these marks from French loanwords once the words are well established in our language.
Like most interjections, voilà can be a standalone sentence (usually with an exclamation point), or it can be set apart by commas or em dashes within a sentence. See the examples below for a few punctuation approaches.
On a quest for a very personal (and picturesque) shower gift? Voilà ! Her favorite picture is transformed into a solid gold pendant necklace. [Los Angeles Times]
Sarah and I … took on that hideous notion that “Corporations Are People.” Voila, Actually.org was born: a fact-checking website with added fun. [Guardian]
Your smart phone tells the app where you are, you specify any special happy-hour needs you might have, and—voilà—you’ve got a detailed list of every happy hour around. [Weekly Volcano]
Under the Ryan plan, we still pay $150 in taxes, only now we get back a voucher worth $150 that we can use to buy health insurance. Voilà! No government deficit. [Truthout]