Using text values of span as numeric values

JavaScript
1

I am reading the innerHtml of two span’s and each are numeric values, for instance a 6 and 14.

I can store them in var’s and detect them, but what I need to try and do is read them as numeric values to use in the if statement, but its not working.

    function countingRecords() {

        var recordsShown = $("#RecordsShown").text();
        var recordsTotal = $("#TotalNumberOfRecords").text();

        alert(recordsShown + recordsTotal);
// this alert shows 614, the 6 is one and 14 the other

        if (recordsShown < recordsTotal) {
            alert("test");
        }
    }
2

While the comparison also works with string numbers, the + operator has three different meanings, depending on the expression:

  • if either operand is a string => string concatenation
  • if both operands are numbers => addition
  • if it’s used as a ‘prefix’ (i.e. (+b)) => type conversion to a number
3

The first alert is just for my benefit really, its the if statement I’m stuck with, its not recognising when the one value is less than the other value in a numeric sense.

Tried this too and again its not working

if ($(recordsShown).val() < $(recordsTotal).val()) {
   $("#TotalNumberOfRecords").after("<span class='returnRecordsToAll'>clear</span>");
   //alert("test");
}

Tried this too and get NaN as the alert

        var recordsShown = parseInt('#RecordsShown');
        var recordsTotal = parseInt('#TotalNumberOfRecords');

        alert(recordsShown + recordsTotal);
4

Ok looks like Ive got it

        var recordsShown = parseInt($('#RecordsShown').text(), 10);
        var recordsTotal = parseInt($('#TotalNumberOfRecords').text(), 10);

        if (recordsShown < recordsTotal) {
            $("#TotalNumberOfRecords").after(" | <span class='returnRecordsToAll'>clear</span>");
        }
5

As previously mentioned, that would have worked even without parseInt().

6

As previously mentioned, that would have worked even without parseInt().

Yeah, but leaning on type coercion isn’t good practice.

7

Especially when it’s incorrect.

Javascript does NOT do implicit type conversion for number string comparitors if it can help it - If passed two number strings as operands of a comparitor, it will do a STRING comparisson between the two - thus, “120” < “20” is TRUE.

1 Like
8

Yeah, it was my understanding that “1” == 1 will return true, but “1” === 1 will not return true because of type.

V/r,

^ _ ^

9

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