Playing with higher-order functions.

higherOrder.js

function makeConcatenater ( left ) {
  return function ( right ) {
    return left + ' ' + right;
  }
}
var addString = makeConcatenater ( 'Hello' );
addString( 'World' );

///////////////////////////////
function makeAdder ( left ) {
  return function ( right ) {
    return left + right;
  }
}
var add5 = makeAdder( 5 );
add5(20)