如何檢查聲明？

Question

我正在處理一個問題，我有一個字符串列表，這只是一個Java代碼。所以如果代碼在方法體之前或之後有任何聲明，那麼這個腳本應該給我一個錯誤。如果變量聲明在方法體內，那麼它應該可以正常工作。
爲前：

int abcs; // This should generate error. 
double cad; //This should generate error. 

Void main(){ 
    int test; //This should not generate error. 

    void test1(){ 
    int test3; //This should not generate error. 
    } 
} 

我已經寫了一個小程序，這一點，但能不能夠得到想要的結果，我的代碼是：

private void check(String line) 

{詮釋計數= 0; int flag = 0;

// is there an open brace on the current line 
    int bracketpos = line.indexOf('{'); 
    // is there a close brace on the current line 
    int closebracketpos = line.indexOf('}'); 
    // is there a semicolon on the current line 
    int charpos = line.indexOf(';'); 

    // increment count if there is an open brace 
    if(bracketpos>=0) 
     ++count; 

    // decrement count if there is a close brace 
    if(closebracketpos>=0) 
     --count; 

    // if there is an open brace on the current line 
    // ...and there's a close brace on the current line 
    // ...and there's a semicolon on the current line 
    // ...and the number of brackets are balanced (count==0) 
    if(bracketpos>=0 && closebracketpos>=0 && charpos>=0 && count==0){ 
     // if the first semicolon appears after the first close brace 
     if(charpos>closebracketpos){ 
      flag =2; 
     } 
     else 
      // the close brace appears after the semicolon, or neither exist 
      flag =0; 
    } 

    else if (charpos >= 0 && count ==0) { 

     flag= 1; 
    } 
    else { 
    flag = 0; 
     // the line does not have a ;,{,} 
    } 

if(flag!=0) 
{ 
     //ERROR 
} 
} 

我正在逐行傳遞我的例子，所以count記錄着「{」和「}」。

問題： 我正在將我的示例逐行添加到check（）中。我想查看示例中是否有任何聲明。但是，如果方法體內有任何聲明，那麼它很好，但是如果方法體外面有聲明，那麼我的check（）會提示/或給我一個錯誤。

Answer 1

我嘗試終於得到它的工作，唯一的問題是計數初始化爲0，每次檢查（）被調用。

所以我想出了兩個選擇，要麼計數靜態全局int。 或者用check（）傳遞計數值，並且應該返回更新的計數以便保留「{」和「}」的記錄。

Answer 2

你的邏輯錯誤。您應該添加註釋，說明代碼在每個階段執行的操作。這裏有讓你開始...

private void check(String line) 
{  int count = 0; 
     int flag = 0; 

     // is there an open brace on the current line 
     int bracketpos = line.indexOf('{'); 
     // is there a close brace on the current line 
     int closebracketpos = line.indexOf('}'); 
     // is there a semicolon on the current line 
     int charpos = line.indexOf(';'); 

     // increment count if there is an open brace 
     if(bracketpos>=0) 
      ++count; 

     // decrement count if there is a close brace 
     if(closebracketpos>=0) 
      --count; 

     // if there is an open brace on the current line 
     // ...and there's a close brace on the current line 
     // ...and there's a semicolon on the current line 
     // ...and the number of brackets are balanced (count==0) 
     if(bracketpos>=0 && closebracketpos>=0 && charpos>=0 && count==0){ 
      // if the first semicolon appears after the first close brace 
      if(charpos>closebracketpos){ 
       flag =2; 
      } 
      else 
       // the close brace appears after the semicolon, or neither exist 
       flag =0; 
     } 

     else if (charpos >= 0 && count ==0) { 

      flag= 1; 
     } 
     else { 
     flag = 0; 
      // the line does not have a ;,{,} 
     } 

    if(flag!=0) 
{ 
     //ERROR 
    } 
}