index(subsring, beginIndex, endIndex) — Python Technical Interview Questions & Answers

index(subsring, beginIndex, endIndex)

index(subsring, beginIndex, endIndex)

  • index is a string helper. You call it on text like "Asha" or "banana". It gives a new string (or a number/True-False). The old string does not change unless you assign the result back.
  • index(subsring, beginIndex, endIndex) — output: 1. Missing would raise ValueError (unlike find).
  • Fresher trap: writing s.index() and expecting s to update. Strings are immutable. Write s = s.index(...) if you need the new value (when it returns a string).

Technical Interview Tip: Call index on one real word and say what prints.

Code Examples for index(subsring, beginIndex, endIndex)

Example

# index(subsring, beginIndex, endIndex)
print("Asha".index("s"))

index(subsring, beginIndex, endIndex) — output: 1. Missing would raise ValueError (unlike find).

How to Explain index(subsring, beginIndex, endIndex) to an Interviewer

Explain index(subsring, beginIndex, endIndex) as if you are teaching a junior — definition, then one tiny script.

index works on str. index usually returns a new string.

What does the example print, and why?

index(subsring, beginIndex, endIndex) — output: 1

What mistake do freshers make with index(subsring, beginIndex, endIndex)?

index does not change the original string in place.