Precision problems and solutions of JS decimal conversion percentage

because JS Its own mechanism , If you multiply by 100+% String splicing will cause accuracy problems

 for example ：
（0.359*100）% -> 3.5900000000000003%

Solution 1 ：

parseFloat((num * 100).toPrecision(12))+"%" // toPrecision  Format the number to the specified length 

Solution 2 ：

	// num Is the target number ,n Is the accuracy （ Keep a few decimal places ）
	function formatFloat (num, n=2) {
    
      let f = parseFloat(num);
      if (isNaN(f)) return false;
      f = Math.round(num * Math.pow(10, n)) / Math.pow(10, n); // floor  House  round  rounding  ceil  Enter into 
      let s = f.toString();
      let rs = s.indexOf('.');
      // Determine if it is an integer , Add the decimal point and fill in 0
      if (rs < 0) {
    
        rs = s.length;
        s += '.';
      }
      while (s.length <= rs + n) {
    
        s += '0';
      }
      return s;
    }

formatFloat(0.359*100)% -> 3.59%