Fix JSON.parse “Unexpected token” errors

This error means your input is not valid JSON at a specific character position.

1. Check for single quotes ('text') — JSON needs double quotes.
2. Remove trailing commas in objects/arrays.
3. Make sure you are parsing JSON, not HTML (responses starting with <).
4. Verify escaped characters inside strings.

// Invalid
{'name':'Kim',}

// Valid
{"name":"Kim"}