I have a variable in JavaScript:
var text = "i HATE you[i LOVE you]"
The code below originated from VB. I've checked it against W3Schools but I cannot see why it won't work.
var test = text.Substring(text.IndexOf("[") + 1, text.IndexOf("]") - text.IndexOf("[") - 1);
document.write(test);
Javascript is case sensetive, so it doesn't have any Substring or IndexOf methods, it has substring and indexOf methods. However, the .NET method SubString corresponds to the Javascript method substr:
var test = text.substr(text.indexOf("[") + 1, text.indexOf("]") - text.indexOf("[") - 1);
The second parameter is the "end index", not the "length". Or you can use regex.
Reasons why your current solution fails:
javascript is case-sensitive you trying to call String.IndexOf won't work, instead you have to write it as indexOf.
same reason as previous list entry, SubString should be written as substring, in the method you are using it seems like you are looking for substr (because of your arguments).
Alternative solutions
There are several ways to simplify your method of getting the text inbetween [and ], I wrote three examples below.
text.substring (text.indexOf ('[')+1, text.lastIndexOf (']'));
text.substr (n=text.indexOf('[')+1, text.indexOf (']')-n);
text.split (/\[|\]/)[1];
text.match (/\[(.*?)\]/)[1];
Not sure what output you're expecting, but the obvious issue is that your casing is wrong. Method names are case sensitive. You'd need this instead:
text.substring(text.indexOf("[") + 1, text.indexOf("]") - text.indexOf("[") - 1);
"i HATE you"or"[i LOVE you]"?