Click Replace and note that digit disappers, group $0 is seemingly empty. Samething happen if Replace with: /0 and $1,/1.

正则表达式是用于匹配字符串中字符组合的模式。在 JavaScript 中，正则表达式也是对象。这些模式被用于 RegExp 的 exec 和 test 方法, 以及 String 的 match、replace、search 和 split 方法。语法： let expession = /pattern/flags 或者 let expession = new RegExp('pattern', ...

The endogenous repertoire harbors self-reactive CD4 + T cell clones that adopt a follicular helper T cell-like phenotype at steady state Figure 1: Two classes of regulatory T cells can be envisioned.