Concatenate a string and an integer?

tomot

Does Ruby have this ability? It appear to me it does not, unless my search and coding is in error.

For example:

opposite=4; adjacent=3; angle=Math.atan(4/3).radians
45.0
string=".degrees"
.degrees
angle1=angle+string
Error: #<TypeError: (eval):4542:in `+': String can't be coerced into Float>
(eval):4542
(eval):4542

FYI: Autolisp: can concatenate a string and an integer: such that

angle1=angle+string
45.degrees

Aerilius

In ruby objects have a certain type and you can rely on that the type does not magically change on its own.
For a number, the + method is defined to accept another number as argument and returns a number (that you don't want).
For a string, the + concatenates strings and returns the resulting string, so you have to convert any object into a string first.

There are many ways to create strings:
string concatenation:
90.to_s + " degrees" # slow because it creates a new third string object
string appending:
90.to_s << " degrees" # faster because it adds the second string into the first
string interpolation:
"#{90} degrees"

tomot

thanks for the explanation Aerilius:

opposite=4; adjacent=3; angle=Math.atan(4/3).radians
45.0
string=".degrees"
.degrees
angle1=angle.to_s << ".degrees"
45.0.degrees

Its also great news because it finally allows me to make the acceptable 45.0.degrees substitution into the Sine Law that TIG was so kind to put into Ruby form.
http://sketchucation.com/forums/viewtopic.php?f=180&t=53118

thomthom

@aerilius said:

There are many ways to create strings:
string concatenation:
90.to_s + " degrees" # slow because it creates a new third string object
string appending:
90.to_s << " degrees" # faster because it adds the second string into the first
string interpolation:
"#{90} degrees"

Note that string interpolation is the fastest. (And reads easier IMO)