Golang : How to search a list of records or data structures


Tags : golang search-record data-structures world-cities-population

Got a newbie that asked me how to search a list of records(data structures) for specific item and below is a simple example on how to search or iterate a list of records using Golang.

What this simple program does is to demonstrate how to iterate through a list of records and look for a specific name that matches the search key. Once the record is found, return the record for further processing.

Here you go!


 package main

 import (
  "fmt"
  "strings"
 )

 type citySize struct {
  Name string
  Population float64
 }

 // cities with the largest population in the world
 var citiesList = []citySize{
  {"Tokyo", 38001000},
  {"Delhi", 25703168},
  {"Shanghai", 23740778},
  {"Sao Paulo", 21066245},
 }

 func findRecordsByCityName(name string) bool {
  for _, v := range citiesList {
 // convert to lower case for exact matching
 if strings.ToLower(v.Name) == strings.ToLower(name) {
 return true
 }
  }
  return false
 }

 func returnRecordsByCityName(name string) citySize {
  for _, v := range citiesList {
 // convert to lower case for exact matching
 if strings.ToLower(v.Name) == strings.ToLower(name) {
 return v
 }
  }
  return citySize{"", 0}
 }

 func main() {

  if !findRecordsByCityName("New York") {
 fmt.Println("New York is not in the list!")
  }

  // Check if Tokyo is in the list
  cityData := returnRecordsByCityName("Tokyo")
  if cityData.Name != "" {
 fmt.Println(cityData)
  }

  // Check if Teluk Intan is in the list
  cityData = returnRecordsByCityName("Teluk Intan")
  if cityData.Name != "" {
 fmt.Println(cityData)
  } else {
 fmt.Println("Teluk Intan is not in the list")
  }

 }

Output:

 New York is not in the list!
 {Tokyo 3.8001e+07}
 Teluk Intan is not in the list

Happy coding!

Reference:

https://www.socketloop.com/tutorials/golang-check-if-item-is-in-slice-array

  See also : Golang : How to filter a map's elements for faster lookup



Tags : golang search-record data-structures world-cities-population

By Adam Ng(黃武俊)

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