How to get integer with regular expression in kotlin? - regex

Question

ViewModel
fun changeQty(textField: TextFieldValue) {
val temp1 = textField.text
Timber.d("textField: $temp1")
val temp2 = temp1.replace("[^\\d]".toRegex(), "")
Timber.d("temp2: $temp2")
_qty.value = textField.copy(temp2)
}
TextField
OutlinedTextField(
modifier = Modifier
.focusRequester(focusRequester = focusRequester)
.onFocusChanged {
if (it.isFocused) {
keyboardController?.show()
}
},
value = qty.copy(
text = qty.text.trim()
),
onValueChange = changeQty,
label = { Text(text = qtyHint) },
singleLine = true,
keyboardOptions = KeyboardOptions(
keyboardType = KeyboardType.Number,
imeAction = ImeAction.Done
),
keyboardActions = KeyboardActions(
onDone = {
save()
onDismiss()
}
)
)
Set KeyboardType.Number, it display 1,2,3,4,5,6,7,8,9 and , . - space.
I just want to get integer like -10 or 10 or 0.
But I type the , or . or -(not the front sign), it show as it is.
ex)
typing = -10---------
hope = -10
display = -10---------
I put regular expression in
val temp2 = temp1.replace("[^\\d]".toRegex(), "")
But, it doesn't seem to work.
How I can get only integer(also negative integer)?

Answer 1

Use this regex (?<=(\d|-))(\D+) to replace all non digit characters, except first -.
fun getIntegersFromString(input: String): String {
val pattern = Regex("(?<=(\\d|-))(\\D+)")
val formatted = pattern.replace(input, "")
return formatted
}
Check it here