Format and remove en/02.3.md spaces

Author: vcaesar

en/02.2.md

@@ -124,9 +124,9 @@ We just talked about how Go uses the UTF-8 character set. Strings are represente
 var frenchHello string  // basic form to define string
 var emptyString string = ""  // define a string with empty string
 func test() {
-    	no, yes, maybe := "no", "yes", "maybe"  // brief statement
-    	japaneseHello := "Ohaiou"
-    	frenchHello = "Bonjour"  // basic form of assign values
+    no, yes, maybe := "no", "yes", "maybe"  // brief statement
+    japaneseHello := "Ohaiou"
+    frenchHello = "Bonjour"  // basic form of assign values
 }
 ```
 It's impossible to change string values by index. You will get errors when you compile the following code.
@@ -168,7 +168,7 @@ Go has one `error` type for purpose of dealing with error messages. There is als
 ```Go
 err := errors.New("emit macho dwarf: elf header corrupted")
 if err != nil {
-    	fmt.Print(err)
+    fmt.Print(err)
 }
 ```	
 ### Underlying data structure
@@ -201,20 +201,20 @@ var prefix string
 Group form.
 ```Go
 import(
-    	"fmt"
-    	"os"
+    "fmt"
+    "os"
 )
 
 const(
-    	i = 100
-    	pi = 3.1415
-    	prefix = "Go_"
+    i = 100
+    pi = 3.1415
+    prefix = "Go_"
 )
 
 var(
-    	i int
-    	pi float32
-    	prefix string
+    i int
+    pi float32
+    prefix string
 )
 ```	
 Unless you assign the value of constant is `iota`, the first value of constant in the group `const()` will be `0`. If following constants don't assign values explicitly, their values will be the same as the last one. If the value of last constant is `iota`, the values of following constants which are not assigned are `iota` also.
@@ -224,11 +224,11 @@ Unless you assign the value of constant is `iota`, the first value of constant i
 Go has one keyword called `iota`, this keyword is to make `enum`, it begins with `0`, increased by `1`.
 ```Go
 const(
-    	x = iota  // x == 0
-    	y = iota  // y == 1
-    	z = iota  // z == 2
-    	w  // If there is no expression after the constants name, it uses the last expression, 
-    	//so it's saying w = iota implicitly. Therefore w == 3, and y and z both can omit "= iota" as well.
+    x = iota  // x == 0
+    y = iota  // y == 1
+    z = iota  // z == 2
+    w  // If there is no expression after the constants name, it uses the last expression, 
+    //so it's saying w = iota implicitly. Therefore w == 3, and y and z both can omit "= iota" as well.
 )
 
 const v = iota // once iota meets keyword `const`, it resets to `0`, so v = 0.
@@ -363,8 +363,8 @@ For instance, in the case of `aSlice` and `bSlice` above, if you change the valu
 - The length of `slice`.
 - Capacity, the length from start index to end index of `slice`.
 ```Go
-	Array_a := [10]byte{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'}
-	Slice_a := Array_a[2:5]
+Array_a := [10]byte{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'}
+Slice_a := Array_a[2:5]
 ```
 The underlying data structure of the code above as follows.
 
@@ -419,9 +419,9 @@ rating := map[string]float32 {"C":5, "Go":4.5, "Python":4.5, "C++":2 }
 //exist，'ok' returns false. It returns true otherwise.
 csharpRating, ok := rating["C#"]
 if ok {
-    	    fmt.Println("C# is in the map and its rating is ", csharpRating)
+    fmt.Println("C# is in the map and its rating is ", csharpRating)
 } else {
-            fmt.Println("We have no rating associated with C# in the map")
+    fmt.Println("We have no rating associated with C# in the map")
 }
 
 delete(rating, "C")  // delete element with key "c"