<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>js千分位逗號隔開</title> </head> <body> <script > var a = 222122122.6754; var b = a.toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,');//使用正則替換，每隔三個數加一個',' console.log(b) </script> </body> </html>
運行結果：222,122,122.68