console.clear();

​

function trim(string) {

  return string.trim();

}

​

var string = ' A ';

​

console.log(trim(string));

console.log(String.prototype.trim.call(string));

​

var array = [' A', 'B ', ' C '];

​

console.log(array.map(trim));

console.log(array.map(String.prototype.trim.call));

​