如何在Javascript中替换字符串的特定部分

Question

I have a string that looks like this

ATOM LEU 0.1234 C 0.123 0.32 0.34

How do I replace the C with .replace() to & in Javascript by getting only the location of C ? The letter of C can essentially be anything.

I want

ATOM LEU 0.1234 & 0.123 0.32 0.34.

Answer 1

You can do it by using substring() ,

var str = "ATOM LEU 0.1234 C 0.123 0.32 0.34";
var res = str.substring(0, 16) + "&" + str.substring(17);
console.log(str); //"ATOM LEU 0.1234 & 0.123 0.32 0.34"

Answer 2

var str = "ATOM LEU 0.1234 C 0.123 0.32 0.34";
var newStr = str.replace(str.charAt(16), "&");

Answer 3

You can also try this :

var str = "ATOM LEU 0.1234 C 0.123 0.32 0.34";
var strExp = str.split(" ");
var newStr = str.replace(strExp[3], "&");
console.log(newStr);

Answer 4

Find the location of the string you want to replace. Then replace it with what you want. I wrote this not knowing how long the string you want to replace will be.

var str = "ATOM LEU 0.1234 C 0.123 0.32 0.34";
var strToReplace = "C";
var indexOfStrToReplace = str.indexOf(strToReplace);
var result = str.substring(0,indexOfStrToReplace) + "&" + str.substing(indexOfC + strToReplace.length);