string-functions

src/051-string-functions/string-functions.go

@@ -1,26 +1,44 @@
 // ## String Functions
 
+// The standard library's `strings` package provides many
+// useful string-related functions. 
+
 package main
 
 import "strings"
-import "fm"
+import "fmt"
 
-func p(o interface{}) {
-    fmt.Println(o)
+// Helper for all the printing we'll do in this example.
+func p(o ...interface{}) {
+    fmt.Println(o...)
 }
 
 func main() {
-    p("hello"[0])
-    p(strings.Contains("test", "es"))
-    p(strings.Count("test", "t"))
-    p(strings.HasPrefix("test", "te"))
-    p(strings.HasSuffix("test", "st"))
-    p(strings.Index("test", "e"))
-    p(strings.Join([]string{"a", "b"}, "-"))
-    p(strings.Repeat("a", 5))
-    p(strings.Replace("foo", "o", "0", -1))
-    p(strings.Replace("foo", "o", "0", 1))
-    p(strings.Split("a-b-c-d-e", "-"))
-    p(strings.ToLower("TEST"))
-    p(strings.ToUpper("test"))
+    // Here's a sampling of the functions available in
+    // `strings`. Note that these are all functions from
+    // package, not methods on the string object itself.
+    // This means that we nned pass the string in question
+    // as the first argument to the functions.
+    p("Contains:  ", strings.Contains("test", "es"))
+    p("Count:     ", strings.Count("test", "t"))
+    p("HasPrefix: ", strings.HasPrefix("test", "te"))
+    p("HasSuffix: ", strings.HasSuffix("test", "st"))
+    p("Index:     ", strings.Index("test", "e"))
+    p("Join:      ", strings.Join([]string{"a", "b"}, "-"))
+    p("Repeat:    ", strings.Repeat("a", 5))
+    p("Replace:   ", strings.Replace("foo", "o", "0", -1))
+    p("Replace:   ", strings.Replace("foo", "o", "0", 1))
+    p("Split:     ", strings.Split("a-b-c-d-e", "-"))
+    p("toLower:   ", strings.ToLower("TEST"))
+    p("ToUpper:   ", strings.ToUpper("test"))
+    p()
+
+    // You can find more functions in the [`strings`]()
+    // package docs.
+
+    // Not part of `strings` but worth mentioning here are
+    // the mechanisms for getting the length of a string
+    // and getting a character by index.
+    p("len: ", len("hello"))
+    p("char:", "hello"[1])
 }

src/051-string-functions/string-functions.sh

@@ -0,0 +1,15 @@
+Contains:   true
+Count:      2
+HasPrefix:  true
+HasSuffix:  true
+Index:      1
+Join:       a-b
+Repeat:     aaaaa
+Replace:    f00
+Replace:    f0o
+Split:      [a b c d e]
+toLower:    test
+ToUpper:    TEST
+
+len:  5
+char: 101