In React, the key
prop is a special attribute that you need to include when creating lists of elements. It helps React identify which items have changed, are added, or are removed in a list. When React renders a list of components, it uses the key
attribute to keep track of the individual components and their corresponding DOM elements.
Here's why keys are significant in React lists:
When you render a list of elements without keys, React has to do a lot of work to figure out which items changed, got added, or got removed. This process is called reconciliation. By providing a unique key
for each item, React can efficiently update the UI without re-rendering the entire list.
Keys give elements a stable identity across re-renders. React uses the keys to know which element corresponds to which component. If the order of the elements in the list changes without keys, React might mistakenly associate the wrong element with a component, leading to unexpected behavior.