How to remove first char in kotlin string

Question

I'm trying to make a calculator in Android Studio with Kotlin and I trying to allow users to make numbers negative and positive, but I got only half of it, making number negative, but can't make it so it turns back to positive, for it I need to remove first char in string, someone knows how to do it?

var firstNumber: String = ...
if (firstNumber[0] == '-') {
   firstNumber.
}

If you’re making a calculator you should work with Ints, Longs, or BigDecimals, not Strings. — Tenfour04
– Tenfour04, Commented Jan 22, 2022 at 22:47

onkar.am · Accepted Answer · 2022-01-22 20:35:04Z

20

You can use drop() of String class to remove first char of string.

firstName = firstName.drop(1);

answered Jan 22, 2022 at 20:35

onkar.am

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Mureinik · Accepted Answer · 2022-01-22 20:24:01Z

7

You could use substring:

firstNumber = firstNumber.substring(1);

answered Jan 22, 2022 at 20:24

Mureinik

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1 Comment

Fovvu Over a year ago

thanks bro it worked!

CodeToLife · Accepted Answer · 2025-03-10 23:35:30Z

1

Use

trimStart(c:Char)

E.g. given


    var s1="0myString"

and

    var s2="0000myString"

you will get same result for result in next two expressions

val  result = s1.trimStart('0')  //"myString"

or for

val result = s2.trimStart('0')   //"myString"

answered Mar 10 at 23:35

CodeToLife

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