浮点数转有效位数字问题

1.234 1.24 100.123 100.13 0.00232323 0.01

即保留两位小数 如后面不为0 则前一位加1

代码如下

 function num2Str(num){
 var numStr String(num)
 var dotIndex numStr.indexOf( . )
 if(dotIndex -1) return numStr .00 
 dotIndex dotIndex 2
 var dotStr numStr.substring(dotIndex).split( )
 var judgeFlag dotStr.some(i i! 0 )
 var countNum judgeFlag?0.01:0
 var result String(numStr.substring(0,dotIndex 1)*1 countNum)
 var resultDot result.indexOf( . )
 if(resultDot -1) return result .00 
 var tmp result.substring(resultDot 1)
 var tmpBe result.substring(0,resultDot)
 if(tmp.length 1){
 return tmpBe . tmp 0 
 return result