Simple latitude/longitude object. It uses fraction 1/1000 of minute, but you can easily change code to use seconds instead of it. Value can be set in 3 different ways. You can provide float number and this object will get degrees, minutes and fractions. You can pass object with corresponding values and finally string (as in maskedValueRe variabl…

LatitudeLongitudeObject.js

function LatitudeLongitude(lat){
    this.direction = 1;
    this.degrees = 0;
    this.minutes = 0;
    this.fraction = 0;
    this.fValue = 0;
    this.latitude = (lat != null) ? lat : true;
    this.maxValue = ( this.latitude ) ? 90 : 180;
    this.minValue = -this.maxValue;
}

LatitudeLongitude.prototype.setValue = function(lonlat){
    if ( !isNaN( lonlat ) ){
        this.convertFromVal(lonlat);
    } else if ( typeof lonlat == 'string' ){
        this.convertFromStr(lonlat);
    } else {
        this.convertFromObj(lonlat);
    }
};

LatitudeLongitude.prototype.convertFromVal = function(val){
    this.direction = ( val >= 0 ) ? 1 : -1;
    this.degrees = Math.floor( val * this.direction ) ;
    this.minutes = Math.floor( (val * this.direction - parseFloat(this.degrees) ) * 60 ) ;
    this.fraction = (val * this.direction - this.degrees - ( this.minutes / 60 )) * 6000 ;
    this.fraction = this.fraction.toPrecision(4);
    this.setVal();
};

LatitudeLongitude.prototype.convertFromObj = function(obj){
    this.direction = (obj.direction) ? obj.direction : 1;
    this.degrees = (obj.degrees) ? obj.degrees : 0;
    this.minutes = (obj.minutes) ? obj.minutes : 0;
    this.fraction = (obj.fraction) ? obj.fraction : 0;
    this.setVal();
};

LatitudeLongitude.prototype.convertFromStr = function(st){
    var maskedValueRe = new RegExp('^\\s*(\\d{1,3})°\\s*(\\d{1,2})′\\s*(\\d+\\.?\\d*)(″?)\\s*(N|S|E|W)$'),
        results = maskedValueRe.exec(st);
    if ( results ){
        this.latitude = ( st.indexOf('N') >= 0 || st.indexOf( 'S' ) >= 0 );
        this.direction = ((results[5] == 'N') || (results[5] == 'E')) ? 1 : -1;
        this.degrees = parseFloat( results[1] );
        this.minutes = parseFloat( results[2] );
        this.fraction = parseFloat( results[3] ).toPrecision(4);
        this.setVal();
    } else {
        this.setDefaults();
    }
};

LatitudeLongitude.prototype.setDefaults = function(){
    this.direction = 1;
    this.degrees = 0;
    this.minutes = 0;
    this.fraction = 0;
    this.fValue = 0;
    this.latitude = true;
};

LatitudeLongitude.prototype.setVal = function(){
    var add_min = (this.fraction - (this.fraction % 6000)) / 6000;
    this.fraction = this.fraction % 6000;
    this.minutes = this.minutes + add_min;
    this.degrees = this.degrees + (this.minutes - (this.minutes % 60)) / 60;
    this.minutes = this.minutes % 60;
    if (this.degrees >= this.maxValue()){
        this.degrees = this.maxValue();
        this.minutes = 0;
        this.fraction = 0;
    }
    if (this.degrees <= this.minValue()){
        this.degrees = this.minValue();
        this.minutes = 0;
        this.fraction = 0;
    }
    this.fValue = ((this.fraction / 6000) + (this.minutes / 60) + this.degrees) * this.direction;
};

LatitudeLongitude.prototype.getTextValue = function(){
    return '' + this.degrees + "° " + this.minutes + "′ " + this.fraction.toPrecision(4) + ' ' + this.getDirTextValue();
};

LatitudeLongitude.prototype.getDirTextValue = function(){
    if ( this.latitude ){
        return (this.direction > 0) ? 'N' : 'S';
    } else {
        return (this.direction > 0) ? 'E' : 'W';
    }
};