Javascript验证数字逗号和小数

Question

I want to return the number true if it is a valid number that contains only digits with properly placed decimals and commas, otherwise return the number false. For example: if number is 1,093,222.04 or 0.232567 then my program should return the number true, but if the input were 1,093,22.04 then my program should return the number false. For example:

input: 1,093,222.04 => true
input: 0.232567 => true
input: 1267 => true
input: 1,093,22.04 => FALSE
input: 1.282,04 => FALSE
input: abcd124 => FALSE

I tried this but 1,093,222.04 returns false. It should return true

function isNumber(n) {
    return !isNaN(parseFloat(n)) && isFinite(n);
}

Answer 1

Something like this might help you solve your issue.

I first create a helper function to parse strings into a float. I use a regular expression to remove all characters that are not a period or digit, then I use parse float to turn it from a string into a float.

I have a function to compare test whether or not the string is properly formatted. I first convert the string to a float, then I format the float as the proper locale string. If the correctly formatted string and the string given are both the same, then I return true, otherwise I return false.

This may produce unexpected results when there are strings given that have more than one period.

hopefuly this points you in the right direction, happy coding!🚀

 const sToFloat = s => parseFloat(s.replace(/[^\\d.]/g, "")); function goodStringFormat(str) { const float = sToFloat(str); const formatted = float.toLocaleString(); if (formatted === str) return true; return false; } console.log(` Testing 1,093,22.04 good? ${goodStringFormat("1,093,22.04")} Testing 1,093,222.04 good? ${goodStringFormat("1,093,222.04")} `);

Answer 2

您可以尝试删除 ',' 和input.replaceAll(',','')然后进行验证，但您需要在所有检查后都有格式化程序功能

Answer 3

Try using regex instead

const isNumber = x => !!`${x}`.match(/^\d*(,\d{3})*(\.\d*)?$/)

console.log(isNumber("1,093,222.04")) // true
console.log(isNumber("0.232567")) // true
console.log(isNumber("1267")) // true
console.log(isNumber("1,093,22.04")) // false
console.log(isNumber("1.282,04")) // false
console.log(isNumber("abcd124")) // false

Do note that the function must take in a string, since if you pass in the number itself, the commas , will split the "number" into different parameters