In Chinese texting, the number of 哈's indicates how funny something is: 哈哈 is polite laughter, 哈哈哈哈哈 is genuinely funny. A single 哈 can sound cold or dismissive.
usage
Other laugh expressions: 嘻嘻 (giggle), 呵呵 (often sarcastic online), and the number 233 (from a meme).
