javascript 四舍五入保存n位小数

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/**  * 四舍五入，保留位数为  * @param numberRound   */function roundFun(numberRound,roundDigit){   //四舍五入，保留位数为roundDigit    if (numberRound>=0){  var tempNumber = parseInt((numberRound * Math.pow(10,roundDigit)+0.5))/Math.pow(10,roundDigit);  return tempNumber;  }else{  numberRound1 = -numberRound  var tempNumber = parseInt((numberRound1 * Math.pow(10,roundDigit)+0.5))/Math.pow(10,roundDigit);  return -tempNumber;  }  }