Name Errors in Swift in Swift

TL ; DR:

• A NameError occurs when Swift sees a word it does not recognize. Some examples:

• Misspelling a function name:

  prnt("Heyooo!") // NameError: use of unresolved identifier 'prnt'
  

  
  

• Misspelling a variable name:

  let animal = "parrot"
  print(anmal) // NameError: use of unresolved identifier 'anmal'
  

  
  

• When Swift encounters a name error, it immediately stops executing your code and throws a NameError instead.

Full lesson:

Humans are prone to making mistakes. Humans are also typically in charge of creating computer programs. To compensate, programming languages attempt to understand and explain mistakes made in their programs.

Here are two common errors that we encounter while writing Swift code:

The syntax error:

Syntax errors are mistakes in the use of the Swift language, and are analogous to spelling or grammar mistakes in a language like English. For example, the sentence "Would you some tea?" does not make sense – it is missing a verb.

Syntax error means there is something wrong with the way your program is written. Some examples:

1. Misuse of commas when declaring a string:

let greeting = 'Hey there!"

When we run this code we'll get an error: unterminated string literal.

2. Leaving out a parantheses:

print"Hey")

When we run this code we'll get an error: expected expression.

The reference error:

A reference error occurs when the Swift interpreter sees a word it does not recognize. Some examples:

1. Misspelling a class / function name:

prntln("Hey")

When we run this code we'll get an error: use of unresolved identifier 'prntln'.

2. Using a non-existent variable / Misspelling a variable's name:

let animal = "parrot"
print(aniimal)

When we run this code we'll get an error: use of unresolved identifier 'aniimal'.

Assignment
Follow the Coding Tutorial and let's practice with errors!

Hint
Look at the examples above if you get stuck.