将字符串或者数字转化成英文格式输出
var f = function(a){ var b = String(a); var len = b.length; var j = len % 3; var arr = []; if (len <= 3) {return b}; if (j==0) { return m(arr,b,len,0); }else{ arr[0] = b.substr(0,j); b = b.substr(j); return m(arr,b,len,1); } } var m = function(arr,b,len,k){ for (var i = k; i < len/3; i++) { arr[i] = b.substr(0,3); b = b.substr(3); } return arr.join(","); }
暂时这么写,以后有更好的方式再来更新。
6.10
补充: 第一种方法效率太差
//方法二 console.time("2") function splitStr2(str){ var len = str.length; var n = parseInt(len/3); if (len%3 === 0){ --n; } for(var i = n; i > 0; i--){ str = str.substr(0, len-3*(n+1-i))+","+str.substr(len-3*(n+1-i), 3*(n+1-i)+n-i); } return str; } splitStr2("1234567890"); console.timeEnd("2") //方法三 // console.time("3") function splitStr3(str){ var len = str.length; var n = parseInt(len/3); if (len%3 === 0){ --n; } for (var i = 0; i < n; i++) str += "1"; var tmp = str.split(''); for (var i = len - 1; i > 2; i -= 3){ tmp[i+n] = tmp[i]; tmp[i+n-1] = tmp[i-1]; tmp[i+n-2] = tmp[i-2]; tmp[i+n-3] = ","; n--; } tmp.join(''); } splitStr3("1234567890"); console.timeEnd("3"); //方法四 console.time("4"); function splitstr4 (str) { // body... var tmp = ""; var r = ""; for (var len = str.length,i=len-1; i >= 0; i--) { tmp = str[i] + tmp; if (tmp.length == 3) { r = " ," + tmp + r; tmp = ""; }; }; r = tmp + r; if (len % 3 === 0) { r = r.substr(2); }; return r; } splitstr4("1234567890"); console.timeEnd("4") //方法五 console.time("5") function changeStr(str) { var len = str.length; var n = len % 3; var pat = /\d\d\d/g; var m; var arr = [ ]; if (n != 0) { arr[0] = str.substr(0,n); str= str.substr(n); for (var i = 0; i < len / 3; i++) { m = pat.exec(str); arr[i + 1] = m[0]; } } else { for (var i = 0; i < len / 3; i++) { m = pat.exec(str); arr[i] = m[0]; } } return arr.join(","); } changeStr('123456789') console.timeEnd("5")