2.14. Go language function closure

发布时间 : 2025-10-25 13:32:56 UTC      

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Go language supports anonymous functions and can be used as closures. An anonymous function is an “inline” statement or expression. The advantage of anonymous functions is that you can use variables within the function directly without declaring it.

In the following example, we created a function getSequence() to return another function The purpose of this function is to increment in the closure i variable, the code is as follows:

2.14.1. Example #

package main import "fmt" func getSequence() func() int { i:=0 return func() int { i+=1 return i } } func main(){ /* NextNumber is a function where function i is 0 */ nextNumber := getSequence() /* Call the nextNumber function, increment the i variable by 1 and return */ fmt.Println(nextNumber()) fmt.Println(nextNumber()) fmt.Println(nextNumber()) /* Create a new function nextNumber1 and view the results */ nextNumber1 := getSequence() fmt.Println(nextNumber1()) fmt.Println(nextNumber1()) } 

The result of the above code execution is:

1 2 3 1 2 
《地理信息系统原理、技术与方法》  97

最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。