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Mutating arguments - clarifications from written test.
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| # From LaunchSchool written test 2017-07-07 | |
| def shout(string) | |
| string + "!!!" # => "hello world!!!" # Just an operation, not a method on `string`. Silimar to `1 + 1`. Argument `string` stays coupled to `sentence` | |
| string.upcase! # => "HELLO WORLD" # Mutates the caller | |
| end # => :shout | |
| sentence = "hello world" # => "hello world" | |
| shout(sentence) # => "HELLO WORLD" | |
| puts sentence # => nil | |
| ########################### | |
| def shout(string) | |
| string += "!!!" # => "hello world!!!" # Non-mutating method, shorthand for `string = string + '!!!'`. Saves to new memory address & decouples `string` from `sentence`. ` | |
| string.upcase! # => "HELLO WORLD!!!" # Already decoupled (above), so `string` does not affect `sentence` | |
| end # => :shout | |
| sentence = "hello world" # => "hello world" | |
| shout(sentence) # => "HELLO WORLD!!!" | |
| puts sentence # => nil | |
| ############################ | |
| def shout(string) | |
| string << "!!!" # => "hello world!!!" # Mutates the caller (argument `string` stays coupled to `sentence`) | |
| string.upcase! # => "HELLO WORLD!!!" # Mutates the caller again (argument `string` stays coupled to `sentence`) | |
| end # => :shout | |
| sentence = "hello world" # => "hello world" | |
| shout(sentence) # => "HELLO WORLD!!!" | |
| puts sentence # => nil | |
| # >> HELLO WORLD | |
| # >> hello world | |
| # >> HELLO WORLD!!! |
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