Flutter: trim string after certain NUMBER of characters in dart - flutter

Question

Say I have a string with n number of characters, but I want to trim it down to only 10 characters. (Given that at all times the string has greater that 10 characters)
I don't know the contents of the string.
How to trim it in such a way?
I know how to trim it after a CERTAIN character
String s = "one.two";
//Removes everything after first '.'
String result = s.substring(0, s.indexOf('.'));
print(result);
But how to remove it after a CERTAIN NUMBER of characters?

Answer 1

All answers (using substring) get the first 10 UTF-16 code units, which is different than the first 10 characters because some characters consist of two code units. It is better to use the characters package:
import 'package:characters/characters.dart';
void main() {
final str = "Hello 😀 World";
print(str.substring(0, 9)); // BAD
print(str.characters.take(9)); // GOOD
}
prints
➜ dart main.dart
Hello 😀
Hello 😀 W
With substring you might even get half a character (which isn't valid):
print(str.substring(0, 7)); // BAD
print(str.characters.take(7)); // GOOD
prints:
Hello �
Hello 😀

Answer 2

The above examples will fail if string's length is less than the trimmed length. The below code will work with both short and long strings:
import 'dart:math';
void main() {
String s1 = 'abcdefghijklmnop';
String s2 = 'abcdef';
var trimmed = s1.substring(0, min(s1.length,10));
print(trimmed);
trimmed = s2.substring(0, min(s2.length,10));
print(trimmed);
}
NOTE:
Dart string routines operate on UTF-16 code units. For most of Latin and Cyrylic languages that is not a problem since all characters will fit into a single code unit. Yet emojis, some Asian, African and Middle-east languages might need 2 code units to encode a single character. E.g. '😊'.length will return 2 although it is a single character string. See characters package.

Answer 3

I think this should work.
String result = s.substring(0, 10);

Answer 4

To trim a String to a certain number of characters. The. code below works perfectly well:
// initialise your string here
String s = 'one.two.three.four.five';
// trim the string by getting the first 10 characters
String trimmedString = s.substring(0, 10);
// print the first ten characters of the string
print(trimmedString);
Output:
one.two.th
i hope this helps

Answer 5

You can do this in multiple ways.
'string'.substr(start, ?length) USE :- 'one.two.three.four.five'.substr(0, 10)
'string'.substring(start, ?end) USE :- 'one.two.three.four.five'.substring(0, 10)
'string'.slice(start, ?end) USE :- 'one.two.three.four.five'.slice(0, 10)

Answer 6

To trim all trailing/right characters by specified characters, use the method:
static String trimLastCharacter(String srcStr, String pattern) {
if (srcStr.length > 0) {
if (srcStr.endsWith(pattern)) {
final v = srcStr.substring(0, srcStr.length - 1 - pattern.length);
return trimLastCharacter(v, pattern);
}
return srcStr;
}
return srcStr;
}
For example, you want to remove all 0 behind the decimals
$123.98760000
then, call it by
trimLastCharacter("$123.98760000", "0")
output:
$123.9876