Why does my React list need keys?
Keys help React identify which items changed. When you map an array to elements, every item needs a unique stable key. Forgetting keys or using the array index can cause subtle bugs when the list is reordered or updated.
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More FAQs in Common JSX Mistakes Beginners Make (and How to Avoid Them)
Because JSX is JavaScript and class is a reserved word. Use className for the HTML class attribute and htmlFor for the for attribute to avoid the conflict.
Yes. In JSX, every tag must be closed, either with a closing tag or as a self-closing tag with a slash. Tags like img and input that are self-closing in HTML still need the closing slash in JSX.
No. JSX curly braces accept expressions, not statements. Use a ternary for conditions inside JSX, or compute the value before the return statement and reference it in curly braces.
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