Merge https://github.com/adambard/learnxinyminutes-docs

Added two minor changes in integer division to make it clear

bash.html.markdown

@@ -7,6 +7,7 @@ contributors:
     - ["Alexandre Medeiros", "http://alemedeiros.sdf.org"]
     - ["Denis Arh", "https://github.com/darh"]
     - ["akirahirose", "https://twitter.com/akirahirose"]
+    - ["Anton Strömkvist", "http://lutic.org/"]
 filename: LearnBash.sh
 ---
 
@@ -81,6 +82,17 @@ fi
 echo "Always executed" || echo "Only executed if first command fails"
 echo "Always executed" && echo "Only executed if first command does NOT fail"
 
+# To use && and || with if statements, you need multiple pairs of square brackets:
+if [ $NAME == "Steve" ] && [ $AGE -eq 15 ]
+then
+    echo "This will run if $NAME is Steve AND $AGE is 15."
+fi
+
+if [ $NAME == "Daniya" ] || [ $NAME == "Zach" ]
+then
+    echo "This will run if $NAME is Daniya OR Zach."
+fi
+
 # Expressions are denoted with the following format:
 echo $(( 10 + 5 ))
 

perl6.html.markdown

@@ -92,7 +92,7 @@ sub as-many($head, *@rest) { # the `*@` slurpy will basically "take everything e
                              # but not *after*.
   say @rest.join(' / ') ~ " !";
 }
-say as-many('Happy', 'Happy', 'Birthday'); #=> Happy Birthday !
+say as-many('Happy', 'Happy', 'Birthday'); #=> Happy / Birthday !
                                            # Note that the splat did not consume the parameter before.
 
 ## You can call a function with an array using the "argument list flattening" operator `|`
@@ -127,7 +127,7 @@ sub with-named($normal-arg, :$named) {
 }
 with-named(1, named => 6); #=> 7
 # There's one gotcha to be aware of, here:
-# If you quote your key, Perl 6 won't be able to see it as compile time,
+# If you quote your key, Perl 6 won't be able to see it at compile time,
 #  and you'll have a single Pair object as a positional paramater.
 
 with-named(2, :named(5)); #=> 7
@@ -171,9 +171,9 @@ named-def(def => 15); #=> 15
 
 ### Containers
 # In Perl 6, values are actually stored in "containers".
-# the assignment operator asks the container on the left to store the value on its right
+# The assignment operator asks the container on the left to store the value on its right.
 # When passed around, containers are marked as immutable. Which means that, in a function,
-#  you'll get an error if you try to mutate one of your argument.
+#  you'll get an error if you try to mutate one of your arguments.
 # If you really need to, you can ask for a mutable container using `is rw` :
 sub mutate($n is rw) {
   $n++;
@@ -374,7 +374,7 @@ sub foo(@array [$fst, $snd]) {
   say "My first is $fst, my second is $snd ! All in all, I'm @array[].";
   # (^ remember the `[]` to interpolate the array)
 }
-foo(@tail); #=> My first is 2, my second is 3 ! All in all, I'm 1 2
+foo(@tail); #=> My first is 2, my second is 3 ! All in all, I'm 2 3
 
 
 # If you're not using the array itself, you can also keep it anonymous, much like a scalar:

python.html.markdown

@@ -441,7 +441,10 @@ class Human(object):
     # A class attribute. It is shared by all instances of this class
     species = "H. sapiens"
 
-    # Basic initializer
+    # Basic initializer, this is called when this class is instantiated.
+    # Note that the double leading and trailing underscores denote objects
+    # or attributes that are used by python but that live in user-controlled
+    # namespaces. You should not invent such names on your own.
     def __init__(self, name):
         # Assign the argument to the instance's name attribute
         self.name = name
@@ -528,10 +531,12 @@ def double_numbers(iterable):
 # Note xrange is a generator that does the same thing range does.
 # Creating a list 1-900000000 would take lot of time and space to be made.
 # xrange creates an xrange generator object instead of creating the entire list like range does.
-_xrange = xrange(1, 900000000)
+# We use a trailing underscore in variable names when we want to use a name that 
+# would normally collide with a python keyword
+xrange_ = xrange(1, 900000000)
 
 # will double all numbers until a result >=30 found
-for i in double_numbers(_xrange):
+for i in double_numbers(xrange_):
     print(i)
     if i >= 30:
         break
@@ -544,10 +549,10 @@ for i in double_numbers(_xrange):
 from functools import wraps
 
 
-def beg(_say):
-    @wraps(_say)
+def beg(target_function):
+    @wraps(target_function)
     def wrapper(*args, **kwargs):
-        msg, say_please = _say(*args, **kwargs)
+        msg, say_please = target_function(*args, **kwargs)
         if say_please:
             return "{} {}".format(msg, "Please! I am poor :(")
         return msg

python3.html.markdown

@@ -470,7 +470,10 @@ class Human(object):
     # A class attribute. It is shared by all instances of this class
     species = "H. sapiens"
 
-    # Basic initializer
+    # Basic initializer, this is called when this class is instantiated.
+    # Note that the double leading and trailing underscores denote objects
+    # or attributes that are used by python but that live in user-controlled
+    # namespaces. You should not invent such names on your own.
     def __init__(self, name):
         # Assign the argument to the instance's name attribute
         self.name = name
@@ -556,9 +559,11 @@ def double_numbers(iterable):
 # double_numbers.
 # Note range is a generator too. Creating a list 1-900000000 would take lot of
 # time to be made
-_range = range(1, 900000000)
+# We use a trailing underscore in variable names when we want to use a name that 
+# would normally collide with a python keyword
+range_ = range(1, 900000000)
 # will double all numbers until a result >=30 found
-for i in double_numbers(_range):
+for i in double_numbers(range_):
     print(i)
     if i >= 30:
         break
@@ -571,10 +576,10 @@ for i in double_numbers(_range):
 from functools import wraps
 
 
-def beg(_say):
-    @wraps(_say)
+def beg(target_function):
+    @wraps(target_function)
     def wrapper(*args, **kwargs):
-        msg, say_please = _say(*args, **kwargs)
+        msg, say_please = target_function(*args, **kwargs)
         if say_please:
             return "{} {}".format(msg, "Please! I am poor :(")
         return msg