CODEWITHSUNDEEP
androidkotlin
GrigoriMarkov
GrigoriMarkov

Reputation: 97

Kotlin, Android platform. How to check if the text contains any numbers/symbols/chars?

For starters, I am new to Kotlin and have only been working with Android Studio for 2 weeks.

I'm just trying to check if the EditText field contains any digits/symbols/chars. I tried writing it like this:

    if (editText!!.text.contains(Int)) {
    textView?.text = "ERROR! EDITTEXT FIELD CONTAINS DIGITS!"
}

But it doesn't work like that. How can i check, if text is numeric or not, or maybe contains symbols (like "/?!:;%") for example? Thanks for your help!

Upvotes: 8

Views: 11332

Answers (3)

Pavlo28
Pavlo28

Reputation: 1596

Uppercase letters:

if (yourString.contains("[A-Z]".toRegex())) {
    //do something
}

Lowercase letters:

if (yourString.contains("[a-z]".toRegex())) {
    //do something
}

Numbers:

if (yourString.contains("[0-9]".toRegex())) {
    //do something
}

Special characters:

if (yourString.contains("[!\"#$%&'()*+,-./:;\\\\<=>?@\\[\\]^_`{|}~]".toRegex())) {
    //do something
}

All above characters:

if (yourString.contains("[A-Za-z0-9!\"#$%&'()*+,-./:;\\\\<=>?@\\[\\]^_`{|}~]".toRegex())) {
    //do something
}

Upvotes: 16

Madhu Bhat
Madhu Bhat

Reputation: 15183

Since you need to check if the text contains only letters or not, rather than using a regex for any digits/special characters, you can use a regex with a negation on letters [^A-Za-z], which would mean anything other than letters. So your logic would be

if (editText!!.text.contains(Regex("[^A-Za-z]"))) {
    textView?.text = "ERROR! EDITTEXT FIELD CONTAINS DIGITS/SPECIAL CHARS!"
}

Note that this considers only the English letters.

Upvotes: 6

forpas
forpas

Reputation: 164099

Define a string that contains all the symbols and digits that you want to check:

val symbols = "0123456789/?!:;%"

and then use any:

if (editText!!.text.any {it in symbols}) {
    textView?.text = "ERROR! EDITTEXT FIELD CONTAINS DIGITS/INVALID SYMBOLS!"
}

Upvotes: 3

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