Representing a number as 64 bit float

Representing a number as 64 bit float

function to64bitFloat(number) {
    var i, result = "";
    var dv = new DataView(new ArrayBuffer(8));

    dv.setFloat64(0, number, false);

    for (i = 0; i < 8; i++) {
        var bits = dv.getUint8(i).toString(2);
        if (bits.length < 8) {
            bits = new Array(8 - bits.length).fill('0').join("") + bits;
        }
        result += bits;
    }
    return result;
}

I found that separating the sign, exponent, and mantissa fields made the results easier to read:

function to64bitFloat(number) {
    var i, result = "";
    var dv = new DataView(new ArrayBuffer(8));

    dv.setFloat64(0, number, false);

    for (i = 0; i < 8; i++) {
        var bits = dv.getUint8(i).toString(2);
        if (bits.length < 8) {
            bits = new Array(8 - bits.length).fill('0').join("") + bits;
        }
        result += bits;
    }
    return result.substr(0,1) + " " + result.substr(1,11) + " " + result.substr(12);
}