Go Language Functions

Function is the basic block of code for performing a task.

Go language at least a main () function.

You can divide the different functions via the function logic to perform each function is specified task.

Function declaration tells the compiler function name, return type, and parameters.

Go language standard library provides a variety of built-in functions can use. For example, len () function can accept different types of arguments and returns the type of length. If we pass a string length of the string is returned, if the incoming numbers, the function returns the number contained in the array.

Function definition

Go language function is defined in the following format:

func function_name( [parameter list] ) [return_types] {
   函数体
}

Analytical function definition:

• func: function starts a statement by the func
• function_name: function name, function name and parameter list together constitute the function signature.
• parameter list]: list of parameters, parameter as a placeholder, when the function is called, you can pass a value to the parameter, this value is called the actual parameters. Parameter list specifies the parameter type, order, and number of parameters. Parameter is optional, that function can not contain parameters.
• return_types: return type, the function returns a value. return_types is the data type of the column value. Some functions do not need to return a value, in which case return_types not necessary.
• Body of the function: The function defined set of codes.

Examples

The following examples are max () function code, the function passed two integer parameters num1 and num2, and returns the maximum value of these two parameters:

/* 函数返回两个数的最大值 */
func max(num1, num2 int) int {
   /* 声明局部变量 */
   var result int

   if (num1 > num2) {
      result = num1
   } else {
      result = num2
   }
   return result 
}

Function call

When you create a function, you define a function of what needs to be done to perform the tasks assigned by calling the change function.

Call the function, passing the function parameters and return values, for example:

package main

import "fmt"

func main() {
   /* 定义局部变量 */
   var a int = 100
   var b int = 200
   var ret int

   /* 调用函数并返回最大值 */
   ret = max(a, b)

   fmt.Printf( "最大值是 : %d\n", ret )
}

/* 函数返回两个数的最大值 */
func max(num1, num2 int) int {
   /* 定义局部变量 */
   var result int

   if (num1 > num2) {
      result = num1
   } else {
      result = num2
   }
   return result 
}

The above examples call in main () function max () function, the result is:

最大值是 : 200

Function return multiple values

Go function can return multiple values, for example:

package main

import "fmt"

func swap(x, y string) (string, string) {
   return y, x
}

func main() {
   a, b := swap("Mahesh", "Kumar")
   fmt.Println(a, b)
}

The above examples Implementation of the results:

Kumar Mahesh

Function Arguments

If the function parameters, the variable may be referred to the function parameter.

Parameters as defined in the local variable functions in the body.

Call the function, you can pass parameters in two ways:

By default, Go language is passed by value, that is, during the call will not affect the actual parameters.

Function usage