public class StringConcatenationDemo { public static void main(String[] args) { int num1 = 4; int num2 = 2; String str1 = " goals"; String output = num1 + num2 + str1; output = num1 + (num2 + str1); output = num1 + "" + num2 + str1; boolean b = false; output = b + (num1 + num2 + str1); output = "" + b + num1 + num2 + str1; String str2 = null; String str3 = 6 + str2; String str4 = "goals" + str2; String str5 = "6" + null; } }