How to format a number into thousands, millions and billions with dart/flutter? - flutter

Question

How to get a number converted into something like this: 12K, 1.5M, 4.2B from a normal number like: 134900.

Answer 1

This is a minimalist function, of course you'll have to add validation code to verify if the number is valid before executing the function. Otherwise Enjoy ...
void main() {
double num = 1250;
var myNumber = k_m_b_generator(num);
print(myNumber);
}
String k_m_b_generator(num) {
if (num > 999 && num < 99999) {
return "${(num / 1000).toStringAsFixed(1)} K";
} else if (num > 99999 && num < 999999) {
return "${(num / 1000).toStringAsFixed(0)} K";
} else if (num > 999999 && num < 999999999) {
return "${(num / 1000000).toStringAsFixed(1)} M";
} else if (num > 999999999) {
return "${(num / 1000000000).toStringAsFixed(1)} B";
} else {
return num.toString();
}
}

Answer 2

You can use flutter's NumberFormat class with the compact function.
formatNumber(dynamic myNumber) {
// Convert number into a string if it was not a string previously
String stringNumber = myNumber.toString();
// Convert number into double to be formatted.
// Default to zero if unable to do so
double doubleNumber = double.tryParse(stringNumber) ?? 0;
// Set number format to use
NumberFormat numberFormat = new NumberFormat.compact();
return numberFormat.format(doubleNumber);
}

Answer 3

The answer is not entirely correct. If you test it, you will see what i meant. Base on the answer above, I created this solution:
String numberFormat(int n) {
String num = n.toString();
int len = num.length;
if (n >= 1000 && n < 1000000) {
return num.substring(0, len - 3) + '.' + num.substring(len - 3, 1 + (len - 3)) + 'k';
} else if (n >= 1000000 && n < 1000000000) {
return num.substring(0, len - 6) + '.' + num.substring(len - 6, 1 + (len - 6)) + 'm';
} else if (n > 1000000000) {
return num.substring(0, len - 9) + '.' + num.substring(len - 9, 1 + (len - 9)) + 'b';
} else {
return num.toString();
}
}