Which language for mobile development interview questions?

I’ve been at my first job for over a year and I’m ready to find a new job. During my first year I’ve gained experience in native iOS / Android and Node. For my next job, I want to target iOS positions.

What language should I focus on to prepare for code questions for a mobile development interview?

My fear is that during a code interview I will start blending syntax between Swift / Kotlin / Javascript. For a “leetcode” style question, my preference is Javascript (because it’s “quick and dirty”). Also I’d hate to do a String related question in Swift (no direct index access to characters).

Any opinions / experiences with this? Should I just be ready for all three? Should I not worry about it so much because most interview code never gets compiled?

If it’s specifically IOS then Swift and probably familiarity with ObjC or vice versa. If it’s React Native (and I guess some other stuff), then JS. Kotlin/Java is Android.

It kinda does – all characters in a string are indexed, so you can get/set characters at specific indices easily. String handling in Swift more verbose than JS, but the trade-off is that it’s better in many ways, a lot more specific