Question

所以我正在进行一项任务，我们必须使用嵌套for循环并传递参数来创建树的这张ASCII图片。我不能为我的生活找出它没有编译的错误。

这是来源：

public class Tree{

  public static void main(String [] args){

    drawTree(3,4);     
  }

  public static String drawTree(int n, int h){ //n is number of bodies, h is their height.

    for(int i; i = 1; i <= h; i++){ //Number of tree bodies to create
      drawSegment(n);
      }

//Trunk
    for(int i; i = 1; i <= h - 1; i++){ //Trunk spaces
      System.out.print (" ");    
    }

    System.out.print ("*"); //Trunk Body

    for (int i; i = 1; i <= h - 1; i++){ //Trunk end spaces
      System.out.print (" ");
    }
  }

//Leaves  
  public static String drawSegment(int k){ //Creates the tree's bodies 

    for(int i; i = 1; i <= k; i++){ //Number of lines  

      for(int s; s = 1; s <= k - 1; s++){ //Number of Spaces
    System.out.print (" ");      
      }

      for(int s; s <= (2 * i) - 1; s++){ //Number of Stars
    System.out.print ("*");
      }

      for(int s; s = 1; s <= k - 1; s++){ //Number of End Spaces
    System.out.println (" ");      
      }

     }
   }
}

这些是错误：

Tree.java:10: error: not a statement
    for(int i; i = 1; i <= h; i++){ //Number of tree bodies to create
                    ^
Tree.java:10: error: ')' expected
    for(int i; i = 1; i <= h; i++){ //Number of tree bodies to create
                        ^
Tree.java:10: error: ';' expected
    for(int i; i = 1; i <= h; i++){ //Number of tree bodies to create
                             ^
Tree.java:15: error: not a statement
    for(int i; i = 1; i <= h - 1; i++){ //Trunk spaces
                    ^
Tree.java:15: error: ')' expected
    for(int i; i = 1; i <= h - 1; i++){ //Trunk spaces
                            ^
Tree.java:15: error: ';' expected
    for(int i; i = 1; i <= h - 1; i++){ //Trunk spaces
                                 ^
Tree.java:21: error: not a statement
    for (int i; i = 1; i <= h - 1; i++){ //Trunk end spaces
                     ^
Tree.java:21: error: ')' expected
    for (int i; i = 1; i <= h - 1; i++){ //Trunk end spaces
                             ^
Tree.java:21: error: ';' expected
    for (int i; i = 1; i <= h - 1; i++){ //Trunk end spaces
                                  ^
Tree.java:28: error: not a statement
    for(int i; i = 1; i <= k; i++){ //Number of lines  
                    ^
Tree.java:28: error: ')' expected
    for(int i; i = 1; i <= k; i++){ //Number of lines  
                        ^
Tree.java:28: error: ';' expected
    for(int i; i = 1; i <= k; i++){ //Number of lines  
                             ^
Tree.java:30: error: not a statement
      for(int s; s = 1; s <= k - 1; s++){ //Number of Spaces
                      ^
Tree.java:30: error: ')' expected
      for(int s; s = 1; s <= k - 1; s++){ //Number of Spaces
                              ^
Tree.java:30: error: ';' expected
      for(int s; s = 1; s <= k - 1; s++){ //Number of Spaces
                                   ^
Tree.java:38: error: not a statement
      for(int s; s = 1; s <= k - 1; s++){ //Number of End Spaces
                      ^
Tree.java:38: error: ')' expected
      for(int s; s = 1; s <= k - 1; s++){ //Number of End Spaces
                              ^
Tree.java:38: error: ';' expected
      for(int s; s = 1; s <= k - 1; s++){ //Number of End Spaces
                                   ^
18 errors

我认为它与第一种方法drawTree中的for循环无法找到h有关。但我不知道如何解决它。

Answer 1

替换

for(int i; i = 1; i <= h; i++)

使用：

for(int i = 1; i <= h; i++)

Answer 2

需要

for(int i = 1; i <= h - 1; i++) {}

依此类推for for for循环

Answer 3

在每个for循环中，您执行此操作：

for(int i; i = 1; i <= h; i++){

但它应该是：

for(int i = 1; i <= h; i++){

只有两个; ;

for(init;condition;statement)

Answer 4

使用

for(int i = 1; i <= h; i++)
{
    Your Code.
}

注意：这是FOR LOOP的规则 for（初始化;条件;声明）

Java编译器错误。 for循环不是声明

4 个答案: