diff --git a/site/content/docs/02-component-format.md b/site/content/docs/02-component-format.md index f1563a62c6..71468f3faf 100644 --- a/site/content/docs/02-component-format.md +++ b/site/content/docs/02-component-format.md @@ -42,7 +42,7 @@ Svelte uses the `export` keyword to mark a variable declaration as a *property* --- -You can specify a default initial value for a prop. It will be used if the component's consumer doesn't specify the prop on the component (or if its initial value is `undefined`) when instantiating the component. Note that whenever a prop is removed by the consumer, its value is set to `undefined` rather than the initial value. +You can specify a default initial value for a prop. It will be used if the component's consumer doesn't specify the prop on the component (or if its initial value is `undefined`) when instantiating the component. Note that if the values of props are subsequently updated, then any prop whose value is not specified will be set to `undefined` (rather than its initial value). In development mode (see the [compiler options](/docs#compile-time-svelte-compile)), a warning will be printed if no default initial value is provided and the consumer does not specify a value. To squelch this warning, ensure that a default initial value is specified, even if it is `undefined`.