2.4.1. Go marker #

Go program can be composed of multiple tags, which can be keywords, identifiers, constants, strings, and symbols. As follows GO statement consists of six tags:

fmt.Println("Hello, World!")

The 6 tags are (one per line):

1. fmt
2. .
3. Println
4. (
5. "Hello, World!"
6. )

2.4.2. Line delimiter #

In Go a program, one line represents the end of a statement. Each statement does not need to be like C other languages in the family use semicolons as well. ; at the end, because all of this work will be done by Go compiler completes automatically.

If you plan to write multiple statements on the same line, they must use the ; artificial distinction, but in actual development, we do not encourage this practice.

Here are two statements:

fmt.Println("Hello, World!")
fmt.Println("Novice Tutorial：runoob.com")

2.4.3. Annotation #

Comments will not be compiled, and each package should have related comments.

Single-line comments are the most common form of comments, and you can use them anywhere with // single-line comment at the beginning. Multiline comments, also known as block comments, have been marked with /* start with a */ end. Such as:

// Single-Line Comments
/*
 Author by Novice Tutorial
 I am a multi line comment
 */

2.4.4. Identifier #

Identifiers are used to name variables, types, and other program entities. An identifier is actually a sequence of one or more letters (AbeliZ and axiz) numbers (0,9) and underscores _, but the first character must be a letter or underscore, not a number.

The following are valid identifiers:

mahesh   kumar   abc   move_name   a_123
myname50   _temp   j   a23b9   retVal

The following are invalid identifiers:

• 1ab (starts with a number)

• case ( Go keywords of language)

• a+b (operators are not allowed)

2.4.5. String concatenation #

The string of the Go language can be passed through the + :

package main
import "fmt"
func main() {
    fmt.Println("Google" + "Runoob")
}

GoogleRunoob

2.4.6. Keyword #

The following is listed Go 25 keywords or reserved words that will be used in the code:

In addition to the keywords introduced above Go language also has 36 predefined identifiers:

Programs generally consist of keywords, constants, variables, operators, types, and functions.

These delimiters may be used in the program: parentheses () , square brackets [] and curly braces {} .

These punctuation marks may be used in the program: . , , , ; : and ... .

2.4.7. Spaces in Go language #

The declaration of variables in the Go language must be separated by spaces, such as:

var age int;

The proper use of spaces in the statement can make the program easier to read.

No spaces:

fruit=apples+oranges;

Add a space between variables and operators to make the program look more beautiful, such as:

fruit = apples + oranges;

2.4.8. Format string #

Go use in language fmt.Sprintf format the string and assign a value to the new string:

package main
import (
    "fmt"
)
func main() {
   // %d represents an integer number, %s represents a string
    var stockcode=123
    var enddate="2020-12-31"
    var url="Code=%d&endDate=%s"
    var target_url=fmt.Sprintf(url,stockcode,enddate)
    fmt.Println(target_url)
}

Code=123&endDate=2020-12-31