javascript正则表达式替换输入表单验证

Question

When inputting a string with a format:

the beginning r or R , then some non-digit letters, I want to replace the string with R .

It's in this situation:

onkeyup="this.value=this.value.replace(/^[rR]\D/g,'R')"

But it does not work.

Somebody can help me out? Thanks.

Answer 1

Use the following regex:

     onkeyup="this.value=this.value.replace(/^[rR]\D+/, 'R')";

See this DEMO:

 <input onkeyup="this.value=this.value.replace(/^[rR]\\D+/,'R')" />