// 方法一 function toThousands(num) { var result = [ ], counter = 0; num = (num || 0).toString().split(''); for (var i = num.length - 1; i >= 0; i--) { counter++; result.unshift(num[i]); if (!(counter % 3) && i != 0) { result.unshift(','); } } return result.join(''); }
// 方法二 function toThousands(num) { var result = '', counter = 0; num = (num || 0).toString(); for (var i = num.length - 1; i >= 0; i--) { counter++; result = num.charAt(i) + result; if (!(counter % 3) && i != 0) { result = ',' + result; } } return result; }
// 方法三 function toThousands(num) { var num = (num || 0).toString(), re = /\d{3}$/, result = ''; while ( re.test(num) ) { result = RegExp.lastMatch + result; if (num !== RegExp.lastMatch) { result = ',' + result; num = RegExp.leftContext; } else { num = ''; break; } } if (num) { result = num + result; } return result; }
/ 方法四 function toThousands(num) { var num = (num || 0).toString(), result = ''; while (num.length > 3) { result = ',' + num.slice(-3) + result; num = num.slice(0, num.length - 3); } if (num) { result = num + result; } return result; }
// 方法五 function toThousands(num) { var num = (num || 0).toString(), temp = num.length % 3; switch (temp) { case 1: num = '00' + num; break; case 2: num = '0' + num; break; } return num.match(/\d{3}/g).join(',').replace(/^0+/, ''); }
// 方法六 function toThousands(num) { return (num || 0).toString().replace(/(\d)(?=(?:\d{3})+$)/g, '$1,'); }