保留小数

// keep degree function keepDegree(number, degree) { var arr = (number + "").split("."); if (arr.length > 1) { if (degree > 0) { if (arr[1].length < degree) { for ( var i = 0; i < (degree - arr[1].length); i++) { number += "0"; } } else { number = arr[0] + "." + arr[1].substring(0, degree - 1) + Math.round(parseFloat(arr[1].substring(degree - 1, degree) + "." + arr[1].substring(degree, degree + 1))) } } else { number = Math.round(number); } } else { if (degree > 0) { number = number + "."; for ( var i = 0; i < degree; i++) { number += "0"; } } } return number; }

  原来JavaScript也提供了计算精度方法，Number的toFixed(degree)方法。