var array1 = ["hello", "sam", "how"];

var emptyArray2 = [];

array1.join(" ");

var array1 = ["hello", "sam", "how"], result = [];
array1.forEach(function(currentString) {
    result.push(currentString.charAt(0));  // First character
    result.push(currentString.charAt(currentString.length - 1)); //Last character
});
console.log(result);
# [ 'h', 'o', 's', 'm', 'h', 'w' ]

var array2 =  ["hello", "sam", "how"].map(function(p){return p.substring(1, p.length - 1)})

var array1 = ["hello", "sam", "how"];

var emptyArray2 = [];

array1.forEach(function(item){
 //item.charAt(0) will give character at start of string
 //item.charAt(item.length-1) will give character at end of string
 emptyArray2.push(item.charAt(0),item.charAt(item.length-1));
 //Array.push(..) is to append elements into the array
});
console.log(emptyArray2); // will print ["h","o","s","m","h","w"] in console