function doubleChar(str) {
  // Your code here
  return str.split('').reduce((prev,cur)=> {
    return prev += cur+cur;
  },'');
}
// Given a string, you have to return a string in which each charcter (case-sensitive) is repeated once.
Given a string, you have to return a string in which each charcter (case-sensitive) is repeated once.
Given a string you have to return a string in which each charcter ( case - sensitive ) is repeated once .
function doubleChar(str) {
  return str.split('').reduce((prev,cur)=> {
    return prev += cur+cur;
  },'');
}
function doubleChar ( str ) { return str . split ( '' ) . reduce ( ( prev , cur ) => { return prev += cur + cur ; } , '' ) ; }
Given a string, you have to return a string in which each charcter (case-sensitive) is repeated once.
Given a string you have to return a string in which each charcter ( case - sensitive ) is repeated once .
// Your code here