Parsing error message using substr and indexOf not working

I’m trying to extract a substring from an error message I receive and parse it to JSON. However it seems something with the indexOf or the substring method is not working as expected. Here’s the full …

What value does a substring have if it doesn’t exist?

I have a string, msg. I want to check if the third character in the string exists or not. I’ve tried if (msg.substring(3, 4) == undefined) { … } but this doesn’t work. What would the substring be …

Javascript arrays email substring into full name, firstname and lastname

I know my questions are similar to other questions but I could not figure it. I am practicing javascript. I have arrays of emails. from that email I want to get three out puts of strings fullname, …

How to check if a string contains text from an array of substrings in JavaScript?

Pretty straight forward. In javascript, I need to check if a string contains any substrings held in an array. Answer There’s nothing built-in that will do that for you, you’ll have to write a function for it. If you know the strings don’t contain any of the characters that are special in regular expressions, then you can cheat a bit, like this: …which creates a regular expression that’s a series of alternations for the substrings you’re looking for (e.g., one|two) and tests to see if there are matches for any of them, but if any of the substrings contains any

Javascript – How to check if a string contains multiple substrings

I have multiple sub-strings that I want to find in a single string and if all three are found then do this, if not, do something else. I am kind of stuck on how to set it so that if I get three “…

How to trim a file extension from a String in JavaScript?

For example, assuming that x = filename.jpg, I want to get filename, where filename could be any file name (Let’s assume the file name only contains [a-zA-Z0-9-_] to simplify.). I saw x.substring(0, x.indexOf(‘.jpg’)) on DZone Snippets, but wouldn’t x.substring(0, x.length-4) perform better? Because, length is a property and doesn’t do character checking whereas indexOf() is a function and does character checking. Answer If you know the length of the extension, you can use x.slice(0, -4) (where 4 is the three characters of the extension and the dot). If you don’t know the length @John Hartsock regex would be the right