jquery convert results of decimal into fractions

问题

I have code that converts pixels into inches. But the result is a decimal.

How can I have the result return a fraction for the inch, example: 1/4 instead of .25

Here is the HTML:

<label>Pixels</label>
<input class="calcd" id="calc3" type="text" />
<input class="calcd" id="calc4" type="hidden" value="96" />
<br />Inches <span id="result2"></span>

Here is the Jquery:

$(document).ready(function(){
    $(".calcd").keyup(function(){
        var val1 = parseInt($("#calc3").val());
        var val2 = parseInt($("#calc4").val());
        if ( ! isNaN(val1) && ! isNaN(val2))
        {
            $("#result2").text((val1 / val2).toFixed(2));
        }
    });
});

I see this here on stackoverflow:

where using the var decimal = eval(fraction); will work, but am confused on it.

Here is the JsFiddle

回答1:

2 options you got:

• Working demo =>: http://jsfiddle.net/Nn2yq/ -- Convert a decimal number to a fraction / rational number
• you can use this: https://github.com/ekg/fraction.js

Also you only need one $(document).ready(function () {

hope this helps. :)

COde

$(document).ready(function () {

    $(".calc").keyup(function () {

        var val1 = parseInt($("#calc1").val());
        var val2 = parseInt($("#calc2").val());

        if (!isNaN(val1) && !isNaN(val2)) {
            $("#result").text(val1 * val2);
        }
    });

    $(".calcd").keyup(function () {

        var val1 = parseInt($("#calc3").val());
        var val2 = parseInt($("#calc4").val());

        if (!isNaN(val1) && !isNaN(val2)) {
            $("#result2").text(fraction((val1 / val2).toFixed(2)));
        }
    });
});

//convert a decimal into a fraction
function fraction(decimal) {

    if (!decimal) {
        decimal = this;

    }
    whole = String(decimal).split('.')[0];
    decimal = parseFloat("." + String(decimal).split('.')[1]);
    num = "1";
    for (z = 0; z < String(decimal).length - 2; z++) {
        num += "0";
    }
    decimal = decimal * num;
    num = parseInt(num);
    for (z = 2; z < decimal + 1; z++) {
        if (decimal % z == 0 && num % z == 0) {
            decimal = decimal / z;
            num = num / z;
            z = 2;
        }
    }
    //if format of fraction is xx/xxx
    if (decimal.toString().length == 2 && num.toString().length == 3) {
        //reduce by removing trailing 0's
        decimal = Math.round(Math.round(decimal) / 10);
        num = Math.round(Math.round(num) / 10);
    }
    //if format of fraction is xx/xx
    else if (decimal.toString().length == 2 && num.toString().length == 2) {
        decimal = Math.round(decimal / 10);
        num = Math.round(num / 10);
    }
    //get highest common factor to simplify
    var t = HCF(decimal, num);

    //return the fraction after simplifying it
    return ((whole == 0) ? "" : whole + " ") + decimal / t + "/" + num / t;
}

function HCF(u, v) {
    var U = u,
        V = v
    while (true) {
        if (!(U %= V)) return V
        if (!(V %= U)) return U
    }
}

working screenshot

来源：https://stackoverflow.com/questions/22368529/jquery-convert-results-of-decimal-into-fractions