Perl chomp Function Explained

In Perl, the chomp function is used to remove trailing newline (\n) or carriage return (\r) characters from a string.

When reading strings from a file or user input, it’s common for them to end with a newline or carriage return character. However, in some cases, we may want to remove these ending symbols in order to not be affected while processing the strings.

The chomp function will check the end of a string for newline or carriage return characters, and remove them if present. It will alter the original string and return the result without the trailing characters.

Here is an example:

my $str = "Hello World\n";
chomp($str);
print $str; # 输出 "Hello World"

In the example above, the chomp function removed the newline character at the end of the string, resulting in “Hello World”. If there is no newline or carriage return at the end of the string, the chomp function will not make any changes.

When handling user input or reading files, the chomp function is often used in conjunction with file reading functions to ensure that the resulting string does not include end markers. For example:

print "请输入一个字符串：";
my $input = <STDIN>;
chomp($input);
print "你输入的字符串是：$input\n";

In the provided code, the chomp function is used to remove the newline character at the end of the user input string, preventing any extra newline characters from appearing when displaying the output string.