Regular Expressions 101

^start of line

Non-Capturing Group(?:[^_]*_){3}

{3}repeats the group contents below exactly 3 times:

Negated Character Class[^_]*

*matches any number of characters outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 1([^_]+_[^_]+)

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Non-Capturing Group(?:[^_]+_){3}

{3}repeats the group contents below exactly 3 times:

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Group 2([^_]+_[^_]+)

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Negated Character Class[^_]+

+matches at least one character outside the set below:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

.*any character (except for line terminators), repeated any number of times

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?:[^_]*_){3}([^_]+_[^_]+)_(?:[^_]+_){3}([^_]+_[^_]+).*

New

a_b_c_d_e_f_g_1_2_3_4_5
_b_c_dd_ee_f_g_1_222_333_4_5
b_c_dd_ee_f_g_1_222_333_4_5
_c_dd_ee_ff_g_1_222_333_444_5
c_dd_ee_ff_g_1_222_333_444_55_66
_dd_ee_ff_gg_1_222_333_444_55_66

Substitution

$1_$2