问题
I have an input box in which the user inputs a chemical formula. I am displaying their input back to them in a table, with the following code in my javascript file.
document.getElementById("entered").innerHTML = userIn;
...where "userIn" is the "id" of the input box, and "entered" is the id of the data in my table row.
Now, here's my question:
Is there any way I can change all of the numbers in the formula to subscripts, but leaving the letters unchanged? So if H2O2 is entered, only the 2's become subscripted?
回答1:
Use a simple regex replace as given below
document.getElementById("entered").innerHTML = userIn.replace(/(\d+)/g, '<sub>$1</sub>');
Demo: Fiddle
回答2:
You can use a regex to surround all of the digits in userIn with <sub></sub> tags. The following should work:
userIn.replace(/(\d+)/g, "<sub>$1</sub>");
The + in the regex will group a string of consecutive digits together and the tailing g in the regex says to replace all the strings of digits instead of just replacing the first string of digits in userIn.
来源：https://stackoverflow.com/questions/17311116/javascript-change-all-numbers-in-a-string-to-subscripts