Simple multiplication in JavaScript

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3

I have the Google Maps v3 code, which calculates the distance between two points: 

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Calcular distancia entre cidades (mapas e rotas)</title>
    <script src="http://code.jquery.com/jquery-1.8.1.js"type="text/javascript"></script>
</head>
<body>
    <!-- Parâmetro sensor é utilizado somente em dispositivos com GPS -->
    <script src="http://maps.google.com/maps/api/js?sensor=false"></script><scripttype="text/javascript">
        function CalculaDistancia() {
            $('#litResultado').html('Aguarde...');
            //Instanciar o DistanceMatrixService
            var service = new google.maps.DistanceMatrixService();
            //executar o DistanceMatrixService
            service.getDistanceMatrix(
              {
                  //Origem
                  origins: [$("#txtOrigem").val()],
                  //Destino
                  destinations: [$("#txtDestino").val()],
                  //Modo (DRIVING | WALKING | BICYCLING)
                  travelMode: google.maps.TravelMode.DRIVING,
                  //Sistema de medida (METRIC | IMPERIAL)
                  unitSystem: google.maps.UnitSystem.METRIC
                  //Vai chamar o callback
              }, callback);
        }
        //Tratar o retorno do DistanceMatrixService
        function callback(response, status) {
            //Verificar o Status
            if (status != google.maps.DistanceMatrixStatus.OK)
                //Se o status não for "OK"
                $('#litResultado').html(status);
            else {
                //Se o status for OK
                //Endereço de origem = response.originAddresses
                //Endereço de destino = response.destinationAddresses
                //Distância = response.rows[0].elements[0].distance.text
                //Duração = response.rows[0].elements[0].duration.text
                $('#litResultado').html("<strong>Origem</strong>: " + response.originAddresses +
                    "<br /><strong>Destino:</strong> " + response.destinationAddresses +
                    "<br /><strong>Distância</strong>: " + response.rows[0].elements[0].distance.text +
                    " <br /><strong>Duração</strong>: " + response.rows[0].elements[0].duration.text
                    );
                //Atualizar o mapa
                $("#map").attr("src", "https://maps.google.com/maps?saddr=" + response.originAddresses + "&daddr=" + response.destinationAddresses + "&output=embed");
            }
        }
    </script>
    <table width="100%" cellspacing="0" cellpadding="0" border="0">
        <tbody>
            <tr>
                <td>
                    <label for="txtOrigem"><strong>Endere&ccedil;o de origem</strong></label>
                    <input type="text" id="txtOrigem" class="field" style="width: 400px" />

                </td>
            </tr>
            <tr>
                <td>
                    <label for="txtDestino"><strong>Endere&ccedil;o de destino</strong></label>
                    <input type="text" style="width: 400px" class="field" id="txtDestino" />

                </td>
            </tr>
            <tr>
                <td>
                    <input type="button" value="Calcular dist&acirc;ncia" onclick="CalculaDistancia()" class="btnNew" />
                </td>
            </tr>
        </tbody>
    </table>
    <div><span id="litResultado">&nbsp;</span></div>
    <div style="padding: 10px 0 0; clear: both">
        <iframe width="750" scrolling="no" height="350" frameborder="0" id="map" marginheight="0" marginwidth="0" src="https://maps.google.com/maps?saddr=sãopaulo&daddr=riodejaneiro&output=embed"></iframe>
    </div>
    </body></html>

How can I multiply the distance (response.rows [0] .elements [0] .distance.text) by x30, for example?

Thank you in advance!

(Code credit: Marcelo Aymone )

    
asked by anonymous 18.12.2014 / 13:30

1 answer

3

When you need to multiply in the middle of a string concatenation you need to use parentheses.

In your case where you have: " + response.rows[0].elements[0].distance.text + " you can use this way: 

" + (response.rows[0].elements[0].distance.text * 30) + "

This assuming that response.rows[0].elements[0].distance.text is type: number .

If it is type: string you will need to convert it to first number with parseInt or parseFloat first. In the response code that indicated this value would be the same string, "430 Km". In this case, parseInt reads only the numbers and ignores "Km" by cleaning and converting.

An example would be: 

    " + (parseInt(response.rows[0].elements[0].distance.text, 10) * 30) + "
    
18.12.2014 / 13:32
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