The let: directive in Svelte is used with slots to allow a child component to pass data back to the parent through slot props. This is useful when the parent needs to customize how a child component is rendered while still receiving information generated inside the child.
A child component exposes data through a <slot> by using attributes on the <slot> element. In the parent component, you use the let: directive to capture those values and use them inside the slot content.
In the parent, you can capture the item passed from the child by using the let: directive. This gives you full control over how the data is displayed while keeping the child generic.
You can pass multiple pieces of data from the child slot and capture them using multiple let: variables in the parent.
let:allows the parent to access data provided by the child component's slot.The child must explicitly pass props using attributes on the
<slot>element.let:variables are scoped only to the slot content.Fallback content is used if the parent does not provide slot content.