如何使用正则表达式将下划线转换为驼峰？

Question

如何使用单个 Java/Perl正则表达式搜索和替换将具有下划线的名称转换为驼峰案例名称？

underscore_variable_name -> underscoreVariableName
UNDERSCORE_VARIABLE_NAME -> underscoreVariableName
_LEADING_UNDERSCORE -> leadingUnderscore

我要求单个正则表达式的原因是我想使用Eclipse或Notepad ++搜索和替换来实现这一点.

Answer 1

一些Perl示例:

my $str = 'variable_name, VARIABLE_NAME, _var_x_short,  __variable__name___';

### solution 1
$_ = $str;

$_ = lc;
s/_(\w)/\U$1/g;

say;

### solution 2: multi/leading underscore fix
$_ = $str;

$_ = lc;
s/(?<=[^\W_])_+([^\W_])|_+/\U$1/g;

say;

### solution 3: without prior lc
$_ = $str;

s/(?<=[^\W_])_+([^\W_])|([^\W_]+)|_+/\U$1\L$2/g;

say;

输出:

variableName, variableName, VarXShort,  _variable_name__
variableName, variableName, varXShort,  variableName
variableName, variableName, varXShort,  variableName