JavaScript(JS) JS replace all occurrences of a string

To replace all occurrences of a string in JavaScript, you can use the replace() method with a regular expression. Here's an example:

let str = "hello hello world";
let stringToReplace = "hello";
let replacementString = "hi";

let newStr = str.replace(new RegExp(stringToReplace, "g"), replacementString);

console.log(newStr); // Output: "hi hi world"

In this code, we define a string str that contains some instances of the string we want to replace. We also define a stringToReplace variable that contains the string we want to replace, and a replacementString variable that contains the string we want to replace it with.

We use the replace() method with a regular expression new RegExp(stringToReplace, "g") to replace all instances of the stringToReplace string with the replacementString string. The g flag in the regular expression tells replace() to perform the replacement globally (i.e., on all matches).

Finally, we print the modified string newStr to the console using console.log(). The output should be the original string with all instances of the stringToReplace string replaced with the replacementString string.