1.
    function replace(str1,str2){
    if (str2.length<=0) return str1;
    var s1 =str1;
    for(var i =0;i var s2 = str2[i];
    var reg = new RegExp(s2,”g”);
    var s1 = s1.replace(reg,””);
    }
    return s1;
    }

    2.
    const replace=(str1,str2)=>{
    let newstr1 = str1.split(“”);
    let newstr2 = str2.split(“”);
    let arr = [];
    for (let j=0;j if(!newstr2.includes(newstr[j])){
    arr.push(newstr1[j])
    }
    }
    return arr.join(‘’);
    }

    3.
    var str1 =readline();
    var str2 =”[“+readline()+”]”;
    var reg = new RegExp(str2,”g”);
    var str1 = str1.replace(reg,””);
    print(str1)

    4.
    var str1 = readline();
    var str2 = readline();
    for (let i of str2){
    s1 = s1.replace(new RegExp(i,”g”),””)
    }

    5.
    var readline = reequire(“readline”);
    const rl = readline.createInterface({
    input:process.stdin,
    output:process.stdout,
    });
    var countline = 1;
    var token = [];
    rl.on(“line”,function(line){
    token.push(line);
    if(countline===2 ){
    var str0 = token[0].split(“”);
    var str1 = token[1].split(“”);
    for(var i =0;i if(str0.indexOf(str[i])!==-1){
    str0.splice(str0.indexof(str1[i]),1);
    i—;
    }
    }
    str0=str0.join(“”);
    }else{
    countline++ ;
    }
    })