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JavaScript JavaScript Basics (Retired) Working With Numbers Numbers and Strings

olamilekan oshodi
olamilekan oshodi
959 Points
Posted by olamilekan oshodi
olamilekan oshodi
959 Points

What am i doing wrong. My parsefloat not working.

Here is my code.

var name = 'John Smith';
var visitTime = prompt('What time did you see ' + name + ' today?');
var finishTime = prompt('What time did you leave ' + name + ' today?');
var totalTime = parseFloat('visitTime') + parseFloat('finishTime');
document.write('<h3>WoW! Cool you manage to finish seeing ' + name + ' at ' + totalTime);

I need to put in time which i believe will be decimal number. He said i need to put in a quote in order generate decimal number in return for parseFloat.

2 Answers

miikis
miikis
44,957 Points

In addition to Carlos Federico Puebla Larregle's answer, in order to subtract dates like that, you would need to use the built-in Date object. In fact, a slightly better way of doing what you're trying to do would be something like this:

var name = 'John Smith';
var visitTime = prompt('What time did you see ' + name + ' today?');
var finishTime = prompt('What time did you leave ' + name + ' today?');
// Subtracting two date objects will return their difference in milliseconds 
var totalTimeInMs = new Date(finishTime) - new Date(visitTime); 
// Divide milliseconds by 1000 to get seconds
// Divide seconds by 60 to get minutes 
// Divide minutes by 60 to get hours passed
var totalHours = totalTimeInMs / 1000 / 60 / 60;
// Then you'll have: "Wow! Cool you manage to finish seeing Wilbur in 5 hours"
document.write('<h3>WoW! Cool you manage to finish seeing ' + name + ' in ' + totalHours + ' hours');
olamilekan oshodi
olamilekan oshodi
959 Points
olamilekan oshodi
olamilekan oshodi
959 Points

I guess right Mikis. But now am getting "WoW! Cool you manage to finish seeing John Smith in NaN hours" after running your code.

so have done is, i input random number in the first question and second question to the hours in decimal like. 11.00 - 12.30, should give me 1 hour 30 minute.

or i still doing some thing wrong or maybe my code and your code doesn't work for this particular script

thanks

miikis
miikis
44,957 Points

Right. So, for the above to work, visitTime and finishTime must be a certain format. You can read about all the acceptable formats here.

If you don't want to read that and you just want to get it to work, try a format like this, where today's date and time would be: "March 19, 2016 02:33:30pm".

Here, try this:

var name = 'John Smith';
var today = "March 19, 2016 ";
// Visit time format can now be something like: "2:33:00pm"
var visitTime = today + prompt('What time did you see ' + name + ' today?');
// Finish time format can now be something like: "4:42:00pm"
var finishTime = today + prompt('What time did you leave ' + name + ' today?');
// Subtracting two date objects will return their difference in milliseconds 
var totalTimeInMs = new Date(finishTime) - new Date(visitTime); 
// Divide milliseconds by 1000 to get seconds
// Divide seconds by 60 to get minutes 
// Divide minutes by 60 to get hours passed
// parseInt() so you get an Integer, to simplify things
var totalHours = parseInt(totalTimeInMs / 1000 / 60 / 60);
// Then you'll have: "Wow! Cool you manage to finish seeing Wilbur in 5 hours"
document.write('<h3>WoW! Cool you manage to finish seeing ' + name + ' in ' + totalHours + ' hours');
Carlos Federico Puebla Larregle
Carlos Federico Puebla Larregle
21,074 Points
Carlos Federico Puebla Larregle
Carlos Federico Puebla Larregle
21,074 Points

If you're going to put a variable as an argument to the "parseFloat()" function you have to omit the quotation marks. Like this:

var totalTime = parseFloat(visitTime) + parseFloat(finishTime);

I hope that helps a little bit.