Javascript2

 <script>

    var a,b;
    a=10;
    b=20;
    document.writeln("Add:"+(a+b));
    document.writeln("<br>Sub:"+(a-b));
    document.writeln("<br>Mul:"+(a*b));
    document.writeln("<br>Div:"+(a/b));
    document.writeln("<br>Module:"+(a%b));
    document.writeln("<br>Incre:"+(++a));
    document.writeln("<br>Decr:"+(--b));

    document.writeln("<br>==:"+(a==b));//false
    document.writeln("<br>>:"+(a>b));//false
    document.writeln("<br>>=:"+(a>=b));//false
    document.writeln("<br><:"+(a<b));//true
    document.writeln("<br><=:"+(a<=b));//true
    document.writeln("<br>!=:"+(a!=b));//true

    //&& || !
    var r1=a==b&&a<b;//false && true=false
    var r2=a<b&&a!=b;//true && true=true
    document.writeln("<br>:"+r1);
    document.writeln("<br>:"+r2);

    
</script>