3 ms·
Shouldn't have made an example in the if-statement as it is mostly useless there. But triple ! is very common to negate-and-convert a possibly falsy statement (
by littlecranky67 3y ago
Shouldn't have made an example in the if-statement as it is mostly useless there. But triple ! is very common to negate-and-convert a possibly falsy statement (undefined, null, false/true):
const x: boolean | undefined | null = getValue();
const not_x: boolean = !!!y
I added TS type annotation for clarity, although could be inferred if `getValue` is typed accordingly.
- eropple 3y agoI've seen `!!` and I've seen `!`, but what would `!!!` get you here that the other two don't?
- littlecranky67 3y agonegation plus cast to boolean. See this for more info: https://stackoverflow.com/questions/21154510/the-use-of-the-triple-exclamation-mark https://stackoverflow.com/questions/21154510/the-use-of-the-...