VC++とC#とVB.NETとOracleとJavaとRubyでの正規表現の使用例

最も簡易的と思われる
正規表現の使用例

---

VC++

#include <stdio.h>
#include <regex>

void main()
{
    bool IsMatch = std::regex_search("123aaa456",std::regex("[0-9]+$"));
    puts(IsMatch ? "true" : "false"); //結果はtrue

    std::cmatch matcher;
    std::regex_search("123aaa456", matcher, std::regex("[0-9]+"));
    if (matcher.size() > 0) {
        puts(matcher.begin()->str().c_str()); //結果は123
    }

    std::regex MatchPattern("^([0-9]+)a+([0-9]+)$");
    std::string ReplaceResult = std::regex_replace("123aaa456",MatchPattern, "$1$2");
    puts(ReplaceResult.c_str()); //結果は123456
}

C#

using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main()
    {
        bool IsMatch = Regex.IsMatch("123aaa456", "[0-9]+$");
        string num1 = Regex.Match("123aaa456", "^[0-9]+").Value; //結果は、123
        string num2 = Regex.Replace("123aaa456", "^([0-9]+)a+([0-9]+)$", "$1$2"); //結果は、123456
    }
}

C#のサンプル集 5-2 括弧のキャプチャ内容の取得
.NETの正規表現のドキュメント

VB.NET

imports System.Text.RegularExpressions

Dim IsMatch As Boolean = Regex.IsMatch("123aaa456","[0-9]+$")
Dim num1 As String = Regex.Match("123aaa456","^[0-9]+").Value
Dim num2 As String = Regex.Replace("123aaa456","^([0-9]+)a+([0-9]+)$","$1$2")

.NETの正規表現のドキュメント

Oracle

select case when RegExp_Like(Val,'[0-9]+$')
            then 1 else 0 end as IsMatch,
RegExp_Substr(Val,'^([0-9]+)') as num1,
RegExp_Replace(Val,'^([0-9]+)a+([0-9]+)$','\1\2') as num2
  from (select '123aaa456' as Val from dual);

Oracleの正規表現のドキュメント

Java

boolean IsMatch = "123aaa456".matches("(?m)[0-9]+$");
String num = "123aaa456".replaceAll("(?m)^([0-9]+)a+([0-9]+)$","$1$2");

if ("abcde".matches("^.*(..)\\1.*$")) continue;

Ruby

ConstRegex = Regexp.new('^AB|ABBB|ABC')
hairetu = Array.new
hairetu.push('ABC')
hairetu.push('ABBB')

puts "Pattern #{ConstRegex.source}"
for i in (0..hairetu.length-1)
    willOut = "Line#{i+1} #{hairetu[i]} "
    work = ConstRegex.match(hairetu[i]).to_a[0]
    if work then
        willOut += 'matchs ' + work
    else
        willOut += 'no match'
    end
    puts willOut
end

#実行結果
Pattern ^AB|ABBB|ABC
Line1 ABC matchs AB
Line2 ABBB matchs AB