format

src/main/java/LargeFormatter.java

@@ -0,0 +1,37 @@
+public class LargeFormatter {
+
+    private static final String[] suffixes = {"", "k", "M", "B", "T", "q", "Q", "s", "S", "O", "N"};
+    //private static final String[] suffixes = {"", "k"}; //for large number testing
+
+    //input: 10 230 000 -> 10.23M
+    public String formatBigNumber(double number) {
+        int suffixSize = 0;
+        boolean scientific = false;
+
+        while (number > 999) {
+
+            if(suffixSize == suffixes.length - 1){
+                scientific = true;
+                break;
+            }
+
+            suffixSize++;
+            number /= 1000;
+        }
+
+        if(scientific){
+            int exp = 3 * suffixSize;
+            while(number >= 10){
+                exp++;
+                number /= 10;
+            }
+            return String.format("%.2fE%d", number, exp);
+        } else {
+            if(Math.floor(number) == number){
+                return String.format("%.0f%s", number, suffixes[suffixSize]);
+            } else {
+                return String.format("%.2f%s", number, suffixes[suffixSize]);
+            }
+        }
+    }
+}