正则表达式 - 用逗号和小数表示

Question

^([1-9][0-9]*|0)(\.[0-9]{2})?$

From above regular expression:

• 0.1 ---> not valid
• 0.10 ---> valid
• 10 ---> valid
• 100.00 ---> valid
• -0.1 ---> not valid
• -0.10 ---> not valid
• -10 ---> not valid
• -100.00 ---> not valid

Now I want to add the comma into my regular expression as below:

• 1,000.00 ---> valid
• 10,000.00 ---> valid
• 100,000.00 ---> valid
• 1,000,000.00 ---> valid
• -1,000.00 ---> not valid

How should I correct my regular expression?

Answer 1

In your regular expression you need to change

[1-9][0-9]*

which stand for "one or more digits starting from non-zero", to

[1-9][0-9]{0,2}(,[0-9]{3})*

which stands for "one to three digits starting from non-zero [1-9][0-9]{0,2} , followed by any numbers of groups with three digits each (,[0-9]{3})* ".

The resulting regular expression will be:

^([1-9][0-9]{0,2}(,[0-9]{3})*|0)(\.[0-9]{2})?$