Method arguments.

[Sard Aukary]

Is there a way to refer to the arguments passed to a function, so I can
avoid re-stating the argument inside it like the example below?

puts "this is a test"[4.."this is a test".length]

 

[Farrel Lifson]

Is there a way to refer to the arguments passed to a function, so I can
avoid re-stating the argument inside it like the example below?

puts "this is a test"[4.."this is a test".length]

Is there a reason you can't put it in a varialbe beforehand?

string = "this is a test"
puts string[4..string.length]

Farrel

 

[Paul Battley]

Is there a way to refer to the arguments passed to a function, so I can
avoid re-stating the argument inside it like the example below?

puts "this is a test"[4.."this is a test".length]

In this case, it's unnecessary:

"this is a test"[4..-1]

Paul

 

[Ben Nagy]

But one general method of avoiding assignment or restatement is
instance_eval

"this is a test".instance_eval {self[4..self.length]}

ben

-----Original Message-----
From: Paul Battley [mailto[email protected]]
Sent: Thursday, August 10, 2006 6:27 PM
To: ruby-talk ML
Subject: Re: Method arguments.

Is there a way to refer to the arguments passed to a function, so I can
avoid re-stating the argument inside it like the example below?

puts "this is a test"[4.."this is a test".length]

In this case, it's unnecessary:

"this is a test"[4..-1]

Paul

 

[Jim Weirich]

Is there a way to refer to the arguments passed to a function, so I can
avoid re-stating the argument inside it like the example below?

puts "this is a test"[4.."this is a test".length]

In your particular case, it can be restated as:

puts "this is a test"[4..-1]

Where the -1 refers to the end of the string.

In general, if you have a long expression you wish to refer to twice,
you can

(1) make a local variable:

s = "this is a test"
puts s[4..s.length]

or (2) make a method

def s
"this is a test"
end
# ...
puts s[4..s.length]

I'm not sure how your example relates to function arguments ... but is
this helpfull?

-- Jim Weirich

 

[Sard Aukary]

In your particular case, it can be restated as:

puts "this is a test"[4..-1]

Where the -1 refers to the end of the string.

I'm not sure how your example relates to function arguments ... but is
this helpfull?

-- Jim Weirich

Ah yes, -1 is the most obvious way of to get the end reference.

I was just wondering if there was some sort of reflective way of getting
a reference to the "this is a test" string from with the [] method.

Thanks.

 

[Eero Saynatkari]

In your particular case, it can be restated as:

puts "this is a test"[4..-1]

Where the -1 refers to the end of the string.

I'm not sure how your example relates to function arguments ... but is
this helpfull?

-- Jim Weirich

Ah yes, -1 is the most obvious way of to get the end reference.

I was just wondering if there was some sort of reflective way of getting
a reference to the "this is a test" string from with the [] method.

No, unless you create one. You could conceivably do this
by some extremely evil use of method rerouting, local_variables
and such nefarities.

Just using variable is your best option, though