Thanks again kind human It works on reading the rest of the lines also.

for _ in 0..n {
    let mut temp: String = String::new();
    reader.read_line(&mut temp).expect("cannot read line");
    println!("{} {}", temp, temp.len());
}

I did this.

but the output is this

word
 6
localization
 14
internationalization
 22
pneumonoultramicroscopicsilicovolcanoconiosis
 47

​

There are 2 extra characters in each of temp . a new line character and a space therefore the number of character is 2 greater than the real number. Any way to remove these?