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| author | Geoff Liu <cangming.liu@gmail.com> | 2016-08-02 14:02:23 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2016-08-02 14:02:23 -0400 |
| commit | 3f5106a323be07b55f4140e31db8778640396d09 (patch) | |
| tree | a7bb0f1d33169983c0b266c4203a9e8afdc684f7 /scala.html.markdown | |
| parent | b7bfade6070381d0d4c506b19947adff4dff8c65 (diff) | |
| parent | f1b64fb6a67bf7fa5020a7effd1ace4edbb0a4b0 (diff) | |
Merge pull request #1782 from doub1ejack/scala-en-repl
[scala/en] Added REPL basics to help people experiment as they learn.
Diffstat (limited to 'scala.html.markdown')
| -rw-r--r-- | scala.html.markdown | 60 |
1 files changed, 50 insertions, 10 deletions
diff --git a/scala.html.markdown b/scala.html.markdown index 7f5f0ec3..5e3ece2d 100644 --- a/scala.html.markdown +++ b/scala.html.markdown @@ -12,22 +12,62 @@ Scala - the scalable language ```scala +///////////////////////////////////////////////// +// 0. Basics +///////////////////////////////////////////////// /* - Set yourself up: + Setup Scala: 1) Download Scala - http://www.scala-lang.org/downloads 2) Unzip/untar to your favourite location and put the bin subdir in your `PATH` environment variable - 3) Start a Scala REPL by running `scala`. You should see the prompt: - - scala> - - This is the so called REPL (Read-Eval-Print Loop). You may type any Scala - expression, and the result will be printed. We will explain what Scala files - look like further into this tutorial, but for now, let's start with some - basics. - */ +/* + Try the REPL + + Scala has a tool called the REPL (Read-Eval-Print Loop) that is anologus to + commandline interpreters in many other languages. You may type any Scala + expression, and the result will be evaluated and printed. + + The REPL is a very handy tool to test and verify code. Use it as you read + this tutorial to quickly explore concepts on your own. +*/ + +// Start a Scala REPL by running `scala`. You should see the prompt: +$ scala +scala> + +// By default each expression you type is saved as a new numbered value +scala> 2 + 2 +res0: Int = 4 + +// Default values can be reused. Note the value type displayed in the result.. +scala> res0 + 2 +res1: Int = 6 + +// Scala is a strongly typed language. You can use the REPL to check the type +// without evaluating an expression. +scala> :type (true, 2.0) +(Boolean, Double) + +// REPL sessions can be saved +scala> :save /sites/repl-test.scala + +// Files can be loaded into the REPL +scala> :load /sites/repl-test.scala +Loading /sites/repl-test.scala... +res2: Int = 4 +res3: Int = 6 + +// You can search your recent history +scala> :h? +1 2 + 2 +2 res0 + 2 +3 :save /sites/repl-test.scala +4 :load /sites/repl-test.scala +5 :h? + +// Now that you know how to play, let's learn a little scala... ///////////////////////////////////////////////// // 1. Basics |