Take a look at Example 13-4, in which:
nis assigned the string value
'838102050', the next line prints out its value, and the
typeofoperator is used to look up the type.
nis given the value returned when the numbers 12345 and 67890 are multiplied together. This value is also
838102050, but it is a number, not a string. The type of the variable is then looked up and displayed.
Some text is appended to the number
nand the result is displayed.
<script> n = '838102050' // Set 'n' to a string document.write('n = ' + n + ', and is a ' + typeof n + '<br />') n = 12345 * 67890; // Set 'n' to a number document.write('n = ' + n + ', and is a ' + typeof n + '<br />') n += ' plus some text' // Change 'n' from a number to a string document.write('n = ' + n + ', and is a ' + typeof n + '<br />') </script>
The output from this script looks like:
n = 838102050, and is a string n = 838102050, and is a number n = 838102050 plus some text, and is a string
If there is ever any doubt about the type of a variable, or you need to ensure a variable has a particular type, you can force it to that type using statements such as the following (which ...