If you want to reverse string in javascript then use the reverse() method
var string = "Welcome to Javascript!";
console.log(string.split("").reverse().join(""));
Output:-
!tpircsavaJ ot emocleW
Reverse string without pre defined function
var string = "Welcome to Javascript!";
var arr= string.split("");
var i=0;
var new_arr=[];
for(i=arr.length-1; i>=0; i--){
new_arr.push(arr[i]);
}
console.log(new_arr.join(""));
Output:-
!tpircsavaJ ot emocleW
Reverse only string words
var string = "Welcome to Javascript!";
let data= string.split(" ");
let revdata=[];
for(let i=0; i<(data.length); i++)
{
revdata.push(data[i].split("").reverse().join(""));
}
console.log(revdata.join(" "));
Output:-
emocleW ot !tpircsavaJ