From 18c413f6f55b24d031a37590a85d4e602ac6bceb Mon Sep 17 00:00:00 2001 From: Leah Hanson Date: Mon, 1 Jul 2013 16:21:56 -0400 Subject: edited tuples section --- julia.html.markdown | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) (limited to 'julia.html.markdown') diff --git a/julia.html.markdown b/julia.html.markdown index ff2f2339..b036b1dd 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -109,7 +109,6 @@ Some!Other1Var! = 6 #=> 6 # You can use uppercase letters, digits, and exclamati # * Names of functions and macros are in lower case, without underscores. # * Functions that modify their inputs have names that end in !. These functions are sometimes called mutating functions or in-place functions. - # Arrays store sequences li = Int64[] #=> 0-element Int64 Array # 1-dimensional array literals can be written with comma-separated values. @@ -128,8 +127,8 @@ pop!(other_li) #=> 6 and other_li is now [4,5] # Let's put it back push!(other_li,6) # other_li is now [4,5,6] again. -# Remember that Julia indexes from 1, not 0! -li[1] #=> 1 +li[1] #=> 1 # remember that Julia indexes from 1, not 0! +li[end] #=> 6 # end is a shorthand for the last index; it can be used in any indexing expression. # Function names that end in exclamations points indicate that they modify their argument. arr = [5,4,6] #=> 3-element Int64 Array: [5,4,6] @@ -162,26 +161,22 @@ contains(li,1) #=> true # Examine the length with length length(li) #=> 7 -# Tuples are like lists but are immutable. -tup = (1, 2, 3) -tup[0] #=> 1 -try: - tup[0] = 3 # Raises a TypeError -except TypeError: - print "Tuples cannot be mutated." +# Tuples are immutable. +tup = (1, 2, 3) #=>(1,2,3) # an (Int64,Int64,Int64) tuple. +tup[1] #=> 1 +tup[0] = 3 # ERROR: no method setindex!((Int64,Int64,Int64),Int64,Int64) -# You can do all those list thingies on tuples too -len(tup) #=> 3 -tup + (4, 5, 6) #=> (1, 2, 3, 4, 5, 6) -tup[:2] #=> (1, 2) -2 in tup #=> True +# Many list functions also work on tuples +length(tup) #=> 3 +tup[1:2] #=> (1,2) +contains(tup,2) #=> true # You can unpack tuples into variables -a, b, c = (1, 2, 3) # a is now 1, b is now 2 and c is now 3 +a, b, c = (1, 2, 3) #=> (1,2,3) # a is now 1, b is now 2 and c is now 3 # Tuples are created by default if you leave out the parentheses -d, e, f = 4, 5, 6 +d, e, f = 4, 5, 6 #=> (4,5,6) # Now look how easy it is to swap two values -e, d = d, e # d is now 5 and e is now 4 +e, d = d, e #=> (5,4) # d is now 5 and e is now 4 # Dictionaries store mappings -- cgit v1.2.3