regex101: forAllWorkToIll

<the literal < (60₁₀ / 74₈ / 3C₁₆)

Group tagName(?<tagName>\w+)

\w+any word character, repeated at least once

Group 2((>)|(.+?>))

1st Alternative(>)

Group 3(>)

>the literal > (62₁₀ / 76₈ / 3E₁₆)

2nd Alternative(.+?>)

Group 4(.+?>)

.+?any character, repeated at least once

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Group 5(.+?)?

?repeats the group contents below at most once:

.+?any character, repeated at least once

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

\k<tagName>the text saved by group tagName

>the literal > (62₁₀ / 76₈ / 3E₁₆)

Global pattern flags

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

g modifier: global. Finds all matches instead of stopping after the first

s modifier: single line. Allows a dot to match line terminators

Search reference

Regular Expression

<(?<tagName>\w+)((>)|(.+?>))(.+?)?<\/\k<tagName>>

New

<transaction>
    <id>6753322</id>
    <number region="Russia">8-900-000-00-00</number>
    <nonattr />
    <nonattr></nonattr>
    <nonattr>text</nonattr>
    <attr id="1" />
    <attr id="2"></attr>
    <attr id="3">text</attr>
    <email>
        <to>to_example@gmail.com</to>
        <from>from_example@gmail.com</from>
        <subject>Project discussion</subject>
        <body font="Verdana">Body message</body>
        <date day="12" month="12" year="2018"/>
    </email>
</transaction>

<number region="Russia">8-900-000-00-00</number>


<nonattr></nonattr>

<attr id="2"></attr>

<body font="Verdana">Body message</body>

    <email>
        <to>to_example@gmail.com</to>
        <from>from_example@gmail.com</from>
        <subject>Project discussion</subject>
        <body font="Verdana">Body message</body>
        <date day="12" month="12" year="2018"/>
    </email>

Regular Expressions 101

Regular Expression

Extraction