错误：变量可能尚未初始化和if语句

所以基本上，

//Black ops 2 Class generator Please help me FIX!!!!!! import java.util.Scanner; import java.util.Random; public class money { public static void main(String[]args) { String primaryOption; Scanner scan = new Scanner (System.in); Random primaryGen = new Random(); String weaponType; //Rifle, SMG, HMG, Sniper, shotgun, or special String primaryoption; //Do you want a primary? String primaryWeapon; //The gun you get int primaryWeapon1; String primrayCamo; //Camo for primary String MTAR = "MTAR", Type25 = "Type 25", SWAT556 = "SWAT-556", FALOSW = "FAL-OSW", M27 = "M27", SCARH = "SCAR-H", SMR = "SMR", M8A1 = "M8A1", AN94 = "AN-94"; String secondaryOption; //Do you want a secondary? String secondaryWeapon; //Your gun int secondaryWeapon1; String secondaryCamo; //Camo for secondary System.out.println("Would you like a Primary Weapon? Yes(1) or No(2)"); primaryOption = scan.nextLine(); if (primaryOption.equals("Yes")) { System.out.println("Would you like a Rifle, SMG, HMG, Sniper, Shotgun, or Special?)"); weaponType = scan.nextLine(); if (weaponType.equals("Rifle")) { primaryWeapon1 = primaryGen.nextInt(1) +1; if (primaryWeapon1 == 1) { primaryWeapon = MTAR; //*&%&*This is where i initialized it. } return; } System.out.println("Primary Weapon: " + primaryWeapon); //This is where the error is. It say's im not initializing the variable but I initialize it in the last if statement } } } 

Answer 1

它说我没有初始化变量，但我在最后一个if语句中初始化它

如果没有执行“if”块会发生什么？ 然后该变量将被取消分配吗？ 这就是编译器抱怨的原因。

应在所有可能的流中分配局部变量，否则它是编译时错误。

Answer 2

您必须在使用之前初始化变量。 如果if语句失败，则此变量将保持未初始化状态：

  System.out.println("Primary Weapon: " + primaryWeapon); 

因此，在您声明它的地方，将其等于"" ：

 String primaryWeapon = ""; //The gun you get 

Answer 3

有些情况下， PrimaryWeapon永远不会被初始化（只要PrimaryWeapon1不等于1 ）。

使用它，它已修复：

 String primaryWeapon = ""; 

Answer 4

我认为你的问题在于if语句：假设你到达这里并且weaponType等于“步枪”，它将返回并退出你的函数。 您应该将primaryWeapon初始化为默认值，即primaryWeapon =“None”;

  if (weaponType.equals("Rifle")) { primaryWeapon1 = primaryGen.nextInt(1) +1; if (primaryWeapon1 == 1) { primaryWeapon = MTAR; //*&%&*This is where i initialized it. } return; //<---- remove this } 

同样完成if块， if(yes) {...} else {...}. java编译器将分支出条件子句，并在尝试使用未初始化的变量时发出警告/错误。 例如：

 int b; boolean f = true; if(f) b =1; System.out.println(b); //error because no else block //Fixed int b; boolean f = true; if(f) b = 1; else b= 2; System.out.println(b); 

--Niru