What is wrong with this:
var a = "1";
var b = {};
var b[a] = 'test';
According to this SO question, the above is valid. But var b[a] = 'test' is generating this error in AngularJS (v1):
Uncaught SyntaxError: Unexpected token [
1 Answer
This line:
var b[a] = 'test';
is not valid, because the characters [ and ] are not allowed in variable names.
If you are not wishing to declare a new variable on that line, but rather just assign a key/value pair to the object b, you can just remove the var:
b[a] = 'test'; //b now equals { "1": "test" }
1 Comment
Quangdao Nguyen
Yep, I actually see stuff like this somewhat often among beginners.
var is only required for declaring/"create" a new variable. While b[a] doesn't currently exist, it's not a variable; it's a property of an object belonging to the variable b. In the same manner, you don't need var when assigning a value to an existing var, e.g. a = 2;.
varfrom the third line and it'll be the same as that question.