javascript FormatNumber函数实现方法

调用方法：FormatNumber(r,s);//r要格式化的数字，s保留的位数

function FormatNumber(srcStr,nAfterDot){

var srcStr,nAfterDot;

var resultStr,nTen;

srcStr = ""+srcStr+"";

strLen = srcStr.length;

dotPos = srcStr.indexOf(".",0);

if (dotPos == -1){

resultStr = srcStr+".";

for (i=0;i<nAfterDot;i++){

resultStr = resultStr+"0";

}

return resultStr;

}

else{

if ((strLen - dotPos - 1) >= nAfterDot){

nAfter = dotPos + nAfterDot + 1;

nTen =1;

for(j=0;j<nAfterDot;j++){

nTen = nTen*10;

}

resultStr = Math.round(parseFloat(srcStr)*nTen)/nTen;

return resultStr;

}

else{

resultStr = srcStr;

for (i=0;i<(nAfterDot - strLen + dotPos + 1);i++){

resultStr = resultStr+"0";

}

return resultStr;

}

}

}