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James Kim
8,475 PointsWhy do you need Try and Catch method?
So i have this code on the bottom with Try and Catch method to parse data into JSON format....
if(response.statusCode === 200){
try {
var profile = JSON.parse(body)
printMessage(username, profile.badges.length, profile.points.JavaScript);
catch(error){
printError(error);
}
}else{
printError({
message: "There was an error getting the profile for " + username + ". (" + http.STATUS_CODES[response.statusCode] + ") "
});
}
but I don't understand why there's a try and catch for the parse error when the code works perfectly fine without the try and catch. Code on bottom....
if(response.statusCode === 200){
var profile = JSON.parse(body)
printMessage(username, profile.badges.length, profile.points.JavaScript);
}else{
printError({
message: "There was an error getting the profile for " + username + ". (" + http.STATUS_CODES[response.statusCode]
+ ") "
});
}
So why is the Try and Catch necessary?
Thank you in advance.
- James
2 Answers
Kevin Korte
28,149 PointsBecause without the catch, you can still have a response status code of 200, but the parse fails, and now your program has no way of recovering from it, so it's just going to error out, and possibly display error information to your user, you don't want them to have.
It only works, as you mentioned, when it works, but there is a chance it won't work, now what? So we try something, and if it errors, we catch the error, and do something with it.
If the status code isn't 200, we don't even bother trying to parse the json.
Jeff Lemay
14,268 PointsThat second block of code works fine without the try/catch in your perfect dev environment. But you can't test for all types of errors for all types of users in all types of environments. You add a try/catch block because you never want to have an error be uncaught, think of it like "just in case everything goes haywire".