JS Built-ins
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StringString.prototype.substringintermediate

String.prototype.substring() — start > end swaps arguments

📖 Usage Example
const str = 'Hello, World!'
str.substring(7, 12)   // → 'World'
str.substring(5, 2)    // → 'llo' (args swapped)
str.substring(7)       // → 'World!'

Use substring() to extract characters between two indices, automatically swapping them if start is greater than end.

String.prototype.substring() — Argument Swap

Unlike slice, if start > end, .substring() swaps them automatically.

Challenge: Implement substringSwap(str) that calls substring(5, 2) and relies on auto-swap.

substringSwap('abcdefgh') // → 'cde'  (same as substring(2, 5))
💡 Hints (1)
  • • `str.substring(a, b)` treats the arguments as `substring(min(a,b), max(a,b))`.