Converting Values

The possibilities are endless for the types of values that can be converted from one form to another. Script 17.10 shows just one example: how to convert kilometers to miles.

To convert kilometers to miles:

1. 
var t,expr=prompt('Length in kilometers:','');
The bookmarklet starts by prompting the user for a length in kilometers (Figure 17.23).
Figure 17.23. First, ask for the number to be converted.

2. 
if(isNaN(parseFloat(expr)))
Check to see if the user entered a numeric value.
3. 
{t=expr+' is not a number';}
If not, set t to be an error message.
4. 
else{t='Length in miles is '+Math.round(expr*6214)/10000;}
Otherwise, convert ...

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