正则表达式修饰符：cat|dog|fish
文本“We have three dogs, one fish, but no cats”中包含多少个“cat”、“dog”或“fish”？
3匹配项在此处找到
We have three #s, one #, but no #s(每个匹配项都被替换为 # 字符)
文本“We have three dogs, one fish, but no cats”中包含多少个“cat”、“dog”或“fish”？
3匹配项在此处找到
We have three #s, one #, but no #s(每个匹配项都被替换为 # 字符)