CODEWITHSUNDEEP
stringkotlincontainscase-sensitive
Mojtaba Haddadi
Mojtaba Haddadi

Reputation: 1376

set ignore case value in when expression on strings

I know how to check a string is in another string like this code.

when (myString) {
        in "FirstString"  -> {
                // some stuff
        }
        in "SecondString" -> {
                // some stuff
        }
        else -> {
                // some stuff
        }
}

in keyword under the hood calls this method CharSequence.contains(other: CharSequence, ignoreCase: Boolean = false)

the question is this :

is there any way that in this case i can set ignoreCase = true ?

Upvotes: 1

Views: 1179

Answers (2)

Ilya
Ilya

Reputation: 23105

You can declare an ad-hoc local operator function contains for strings before when:

fun main() {

    operator fun String.contains(other: String): Boolean = this.contains(other, ignoreCase = true)

    when(myString) {
        in "firstString" -> ...
    }
}

This way that function will be invoked for in operator instead of the one declared in the standard library because it's located in the closer scope.

Note, however, that this trick works only if the original contains function is an extension. If it's a member function, it cannot be overridden with an extension.

Upvotes: 4

Shrey Garg
Shrey Garg

Reputation: 1327

You can use toLowerCase() function here :

when (myString.toLowerCase()) {
    in "firststring"  -> {
            // some stuff
    }
    in "secondstring" -> {
            // some stuff
    }
    else -> {
            // some stuff
    }
}

For the cases of when, if they're variables toLowerCase() needs to be called on each of them. But, if they're constants, simple using lower case strings will work - "firststring", "secondstring"

Upvotes: 0

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