货币数值转换千分位

function formatNumber (num) {
    return num.toString().replace(/(\d)(?=(\d{3})+(?!\d))/g, "$1,")
}

console.info(formatNumber(2665));      // 2,665
console.info(formatNumber(102665));    // 102,665
console.info(formatNumber(111102665)); // 111,102,665

对于包含小数点的数值同样是适用的。

console.info(formatNumber(1240.5));    // 1,240.5
console.info(formatNumber(1000240.5)); // 1,000,240.5

Number formatting in JavaScript