js怎么实现重量换算代码的方法
js重量换算代码，js怎么实现重量换算代码的方法代码教程如下：
随便输入一种重量单位的数值
计算结果：转换出其他重量单位的数值
js实现代码：
function WEIGHT_MEASURES() {
this.mTon = 1000;
this.mKilogram = 1;
this.mGram = 0.001;
this.mMilligram = 0.000001;
this.cJin = 0.5;
this.cDan = 50;
this.cLiang = 0.05;
this.cQian = 0.005;
this.avdpPound = 0.45359237;
this.briTon = 2240 * this.avdpPound;
this.usTon = 2000 * this.avdpPound;
this.briCWT = 112 * this.avdpPound;
this.usCWT = 100 * this.avdpPound;
this.briStone = 14 * this.avdpPound;
this.avdpOunce = this.avdpPound / 16;
this.avdpDram = this.avdpPound / 256;
this.avdpGrain = this.avdpPound / 7000;
this.troyPound = 5760 * this.avdpGrain;
this.troyOunce = 480 * this.avdpGrain;
this.troyDWT = 24 * this.avdpGrain;
this.troyGrain = this.avdpGrain;
}
var weight_data = new WEIGHT_MEASURES();
function checkNum(str) {
for (var i = 0; i < str.length; i++) {
var ch = str.substring(i, i + 1);
if (ch != "." && ch != "+" && ch != "-" && ch != "e" && ch != "E" && (ch < "0" || ch > "9")) {
alert("请输入有效的数字");
return false;
}
}
return true
}
function normalize(what, digits) {
var str = "" + what;
var pp = Math.max(str.lastIndexOf("+"), str.lastIndexOf("-"));
var idot = str.indexOf(".");
if (idot >= 1) {
var ee = (pp > 0) ? str.substring(pp - 1, str.length) : "";
digits += idot;
if (digits >= str.length) {
return str;
}
if (pp > 0 && digits >= pp) {
digits -= pp;
}
var c = eval(str.charAt(digits));
var ipos = digits - 1;
if (c >= 5) {
while (str.charAt(ipos) == "9") {
ipos--;
}
if (str.charAt(ipos) == ".") {
var nc = eval(str.substring(0, idot)) + 1;
if (nc == 10 && ee.length > 0) {
nc = 1;
ee = "e" + (eval(ee.substring(1, ee.length)) + 1);
}
return "" + nc + ee;
}
return str.substring(0, ipos) + (eval(str.charAt(ipos)) + 1) + ee;
} else {
var ret = str.substring(0, digits) + ee;
}
for (var i = 0; i < ret.length; i++) {
if (ret.charAt(i) > "0" && ret.charAt(i) <= "9") {
return ret;
}
}
return str;
}
return str;
}
function compute(obj, val, data) {
if (obj[val].value) {
var uval = 0;
uval = obj[val].value * data[val];
if ((uval >= 0) && (obj[val].value.indexOf("-") != -1)) {
uval = -uval;
}
for (var i in data) {
obj[i].value = normalize(uval / data[i], 8);
}
}
}
function resetValues(form, data) {
for (var i in data) {
form[i].value = "";
}
}
function resetAll(form) {
resetValues(form, weight_data);
}
显示效果：重量换算
参考文章：http://www.itmacom.com/gl/33460.html
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