In this post we will see some example of regular expression using which we will find words, non-words, numbers, non-numbers, whitespaces and non-whitespace characters. We will use special characters from regular expression Character classes. These special characters start with the ‘\’ backward slash. There are many more than the ones that I have displayed.
Words(alphanumeric)
We will start with getting words(alphanumeric characters including ‘_’) using regular expression. Here we use small ‘w’.
const wordRegex = /\w/g;
const str = 'hello123_-?!';
str.match( wordRegex ); // Output ['h', 'e', 'l', 'l', 'o', '1', '2', '3', '_']Non-Words(alphanumeric)
Non-words(non-alphanumeric characters excluding ‘_’) using regular expression. We will use capital ‘W’.
const nonWordRegex = /\W/g;
const str = 'hello123_-?!';
str.match( nonWordRegex ); // Output ['-', '?', '!']Number
Get numbers using regular expression. Here we use small ‘d’.
const numberRegex = /\d/g;
const str = 'hello123_-?!';
str.match( numberRegex ); // Output ['1', '2', '3']Non-Number
Get non-numbers using regular expression. Here we us capital ‘D’.
const nonNumberRegex = /\D/g;
const str = 'hello123_-?!';
str.match( nonNumberRegex ); // Output ['h', 'e', 'l', 'l', 'o', '_', '-', '?', '!']Whitespace
Get whitespace characters using regular expression. Here we use small ‘s’.
const whiteSpaceRegex = /\s/g;
const str = 'foo bar';
str.match( whiteSpaceRegex ); // Output [' ']Non-Whitespace
Get non-whitespace characters using regular expression. Here we use capital ‘S’.
const whiteSpaceRegex = /\s/g;
const str = 'foo bar';
str.match( whiteSpaceRegex ); // Output ['f', 'o', 'o', 'b', 'a', 'r']Conclusion
Hope this helps on how using regular expression we can find words, non-words, numbers, non-numbers, whitespaces and non-whitespace characters. See you in my next post. Till then enjoy coding 🙂