function removeLastWord(s) {
// Trim trailing spaces
s = s.trimEnd();
const indexOfLastSpace = s.lastIndexOf(" ");
if (indexOfLastSpace === -1) {
return s; // no space → return original
}
return s.substring(0, indexOfLastSpace);
}
let s;
s = "c c++ c# java go";
s = removeLastWord(s);
console.log("1. " + s);
s = "";
s = removeLastWord(s);
console.log("2. " + s);
s = "go";
s = removeLastWord(s);
console.log("3. " + s);
s = "c# java go ";
s = removeLastWord(s);
console.log("4. " + s);
s = " ";
s = removeLastWord(s);
console.log("5. " + s);
/*
run:
1. c c++ c# java
2.
3. go
4. c# java
5.
*/