The number is converted to a string of the form '-d,ddd,ddd.ddd ', where each 'd' indicates a digit (0-9). The string starts ...

The number is converted to a string of the form '-d,ddd,ddd.ddd…', where each 'd' indicates a digit (0-9). The string starts with a minus sign if the number is negative. Thousand separators are inserted between each group of three digits to the left of the decimal point. The precision specifier indicates the desired number of decimal places.