change first and last char in string
JavaScript
function newStr(str){
if(str.length<=1){
return str+"</br>";
}
var midStr= str.substring(1,str.length-1);
return((str.charAt(str.length-1))+midStr+str.charAt(0)+"</br>");
}
document.write(newStr("a"));
document.write(newStr("ab"));
document.write(newStr("abc"));
document.write(newStr("abcde"));