1.
    var numInt = readline();
    var arr = numInt.split(“”).reverse();
    console.log(arr.toString().replace(/,/g,””))

    2.
    var str4 = readline();
    var len = str4.length;
    var str5 = “”;
    for(var i = len - 1;i>=0;i—){
    str5 +=str[i]
    }

    3.
    var readline = require(“readline”);
    const rl = readline.createInterface({
    input:process.stdin,
    output:process.stdout,
    })
    rl.on(“line”,(line)=>{
    console.log(line.split(‘’).reverse().join(‘’));
    })

    4.
    var readline = require(“readline”);
    const rl = readline.createInterface({
    input:process.stdin,
    ouput:process.stdout,
    })
    rl.on(“line”,()=>{
    var input = data.trim().split(“”).reverse().join(“”);
    console.log(input);
    })