判斷常量語句定義是否合法，合法則輸出分析結果，不合法則輸出原由。
二、不合法原由
1、是否有關鍵字“const”開頭定義
2、是否有“；”結束定義；
3、句子中格式行的空格處理；
4、常量名是否合法（首字符是字母）；
5、整形常量不能有前導零；
6、整形常量中不能有除數字以外的其他字符；
7、字符常量中只能有一個字符；
8、字符型常量不能爲空；
//9、字符串常量不能爲空；
10、浮點型常量“0.”型的，不能有多餘的前導零；
11、浮點型常量中不能有除數字及小數點外的其他字符；
12、浮點型常量中不能出現多個小數點。
三、代碼測試
見《yufa測試數據及測試結果》
四、測試數據意義分析
const a=234,b="asdas",c='f',s=435.345;
正確數據
sconst a=234,b="asdas",c='f',s=435.345;
關鍵字錯誤
const a=234,b="asdas",c='f',s=435.345
句尾無“；”
const a=234,b="asdas",c = 'f' ,s =435.345;
句中有格式空格
const a=234,b="asdas",1c='f',s=435.345;
const a=234,_b="asdas",c='f',s=435.345;
const a=234,,b="asdas",c='f',s=435.345;
常量名錯誤
const a=0234,b="asdas",c='f',s=435.345;
整型常量有前導零
const a=23ed4,b="asdas",c='f',s=435.345;
“整型常量”中有非數字字符
const a=234,b="asdas",c='ff',s=435.345;
“字符型常量”中有多個字符
const a=234,b="asdas",c='',s=435.345;
“字符型常量”值爲空
const a=234,b="",c='f',s=435.345;
“字符串型常量”值爲空
const a=234,b="asdas",c='f',s=00.345;
“浮點型常量”有多餘前導零
const a=234,b="asdas",c='f',s=43sdf5.345;
“浮點型常量”中有非數字非小數點字符
const a=234,b="asdas",c='f',s=43.5.345;
“浮點型常量”中有多個小數點
五、問題分析
程序中仍不能解決的問題有：
1、若字符串中有空格，無法處理，會被直接刪除；
2、若語句中有多餘的或在字符串中有“，”會導致程序崩潰；
3、若語句中有非英文字符，可能會導致程序崩潰。
測試數據：
const a=234,b="asdas",c='f',s=435.345;
sconst a=234,b="asdas",c='f',s=435.345;
const a=234,b="asdas",c='f',s=435.345
const a=234,b="asdas",c = 'f' ,s =435.345;
const a=234,b="asdas",1c='f',s=435.345;
const a=234,_b="asdas",c='f',s=435.345;
const a=234,,b="asdas",c='f',s=435.345;
const a=0234,b="asdas",c='f',s=435.345;
const a=23ed4,b="asdas",c='f',s=435.345;
const a=234,b="asdas",c='ff',s=435.345;
const a=234,b="asdas",c='',s=435.345;
const a=234,b="",c='f',s=435.345;
const a=234,b="asdas",c='f',s=00.345;
const a=234,b="asdas",c='f',s=43sdf5.345;
const a=234,b="asdas",c='f',s=43.5.345;
測試結果:
const a=234,b="asdas",c='f',s=435.345;
@the constent is lagel ,fllow is the result of Analysis:
*********************************
a(int , 234)
b(String , "asdas")
c(char , 'f')
s(float , 435.345)
num_int = 1 ;
num_float = 1 ;
num_char = 1 ;
num_string = 1 ;
*********************************
The Analysis is finish!
Please input a string again!
-------------------------------------------------
sconst a=234,b="asdas",c='f',s=435.345;
It is not a constant declaration statement! <const>
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c='f',s=435.345
It is not a constant! <;>
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c = 'f' ,s =435.345;
@the constent is lagel ,fllow is the result of Analysis:
*********************************
a(int , 234)
b(String , "asdas")
c(char , 'f')
s(float , 435.345)
num_int = 1 ;
num_float = 1 ;
num_char = 1 ;
num_string = 1 ;
*********************************
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",1c='f',s=435.345;
<1c>: the name is illege!
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,_b="asdas",c='f',s=435.345;
<_b>: the name is illege!
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,,b="asdas",c='f',s=435.345;
<,b>: the name is illege!
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=0234,b="asdas",c='f',s=435.345;
<0234> :is not a legal int! <0>
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=23ed4,b="asdas",c='f',s=435.345;
<23ed4> :is not a legal int! <other charecater>
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c='ff',s=435.345;
<'ff'> :is not a legal charThe Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c='',s=435.345;
<''> :is not a legal charThe Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="",c='f',s=435.345;
<""> :is not a legal StringThe Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c='f',s=00.345;
<00.345> :is not a legal float! <00>
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c='f',s=43sdf5.345;
<43sdf5.345> :is not a legal float! <other charecater>
The Analysis is finish!
Please input a string again!
-------------------------------------------------
const a=234,b="asdas",c='f',s=43.5.345;
<43.5.345> :is not a legal float! <.. >
The Analysis is finish!
Please input a string again!
-------------------------------------------------
/* @常量定義語法判斷 @作者：Amy @版本：1.1 */ #include<iostream> #include<string> #include<vector> #include<stdio.h> #include<string.h> #include<ctype.h> using namespace std; struct node //常量定義分析 { string name; //常量名 string in; //常量內容 string type; //常量類型//interger，char,int,float }content; string s,ss; vector<node> ve; int len; int num_int,num_float,num_char,num_string; char a[1000]; bool initial()//初始化,輸入數據 { num_int=0; num_float=0; num_char=0; num_string=0; ve.clear(); if(gets(a)) { s=a; return true; } return false; } bool judge_const()//判斷const是否正確 { int x=s.find(" ",0); ss=s.substr(0,x);//提取關鍵字const for(int i=0;i<s.size();i++) //去掉空格 if(s[i]==' ')s.erase(i--,1); s.copy(a,s.size()-5,5); len=s.size()-5; a[len]='\0'; if(ss!="const")return false; return true; } bool jundge_tail() //判斷是否有“；” { if(a[len-1]!=';')return false; return true; } void sent()//提取語句（每個定義） { int side=0; char name1[20],in[20]; a[len-1]=','; while(sscanf(a+side,"%[^=]%[^,]",name1,in)) { content.name=name1; content.in=in; content.in.erase(0,1); ve.push_back(content); side+=strlen(name1)+strlen(in)+1; if(side==len) //到結尾 break; } } bool judge_name() //判斷常量名是否合語法 { for(int i=0;i<ve.size();i++) if(!isalpha(ve[i].name[0])){ //首字符不是字母 cout<<"<"<<ve[i].name<<">"; return false; } return true; } void classf() //根據常量特徵分類 { for(int i=0;i<ve.size();i++){ if(ve[i].in[0]=='"') //雙引號開始的是字符串 ve[i].type="String",num_string++; else if(ve[i].in[0]=='\'') //單引號開始的是字符 ve[i].type="char",num_char++; else if(ve[i].in.find(".",0)<ve[i].in.size()) //帶小數點的是小數 ve[i].type="float",num_float++; else ve[i].type="int",num_int++; //否則是整數 } } bool judge_content()//判斷常量內容是否正確 { char txt[20]; for(int i=0;i<ve.size();i++){ if(ve[i].type=="int"){ ve[i].in.copy(a,ve[i].in.size(),0); a[ve[i].in.size()]='\0'; if(sscanf(a,"%[0-9]",txt)&&strlen(a)==strlen(txt)); //整數中沒有非數字字符 else { cout<<"<"<<ve[i].in<<"> :is not a legal int! <other charecater>"<<endl; return false; } if(ve[i].in[0]=='0'){ //整數不能前導零 cout<<"<"<<ve[i].in<<"> :is not a legal int! <0>"<<endl; return false; } } if(ve[i].type=="float"){ ve[i].in.copy(a,ve[i].in.size(),0); a[ve[i].in.size()]='\0'; if(sscanf(a,"%[0-9,.]",txt)&&strlen(a)==strlen(txt)); //小數中沒有非數字和非小數點的字符 else { cout<<"<"<<ve[i].in<<"> :is not a legal float! <other charecater>"<<endl; return false; } if(ve[i].in[0]==ve[i].in[1]&&ve[i].in[1]=='0'){ //小數不能前導兩個零 cout<<"<"<<ve[i].in<<"> :is not a legal float! <00>"<<endl; return false; } if(ve[i].in.find(".",ve[i].in.find(".",0)+1)<ve[i].in.size()){//小數中不能有多個小數點 cout<<"<"<<ve[i].in<<"> :is not a legal float! <.. >"<<endl; return false; } } if(ve[i].type=="char"){ if(ve[i].in.size()!=3){ cout<<"<"<<ve[i].in<<"> :is not a legal char";//常量中自能有一個字符 return false; } } else { if(ve[i].in.size()<3){//字符串常量中不能爲空 cout<<"<"<<ve[i].in<<"> :is not a legal String"; return false; } } } return true; } void output()//輸出結果，若無語法問題 { cout<<"@the constent is lagel ,fllow is the result of Analysis:"; cout<<"\n*********************************\n"; for(int i=0;i<ve.size();i++) cout<<ve[i].name<<"("<<ve[i].type<<" , "<<ve[i].in<<")"<<endl; cout<<endl; cout<<"num_int = "<<num_int<<" ;\n"; cout<<"num_float = "<<num_float<<" ;\n"; cout<<"num_char = "<<num_char<<" ;\n"; cout<<"num_string = "<<num_string<<" ;\n"; cout<<"\n*********************************\n"; } int main() { bool x; while(initial()) { if(!judge_const())//判斷是否有關鍵字“const” { cout<<"It is not a constant declaration statement! <const>"<<endl; goto end1; } if(!jundge_tail())//判斷句尾是否有“；” { cout<<"It is not a constant! <;>"<<endl; goto end1; } sent(); if(!judge_name())//判斷常量名是否合法 { cout<<": the name is illege!\n\n"; goto end1; } classf(); //分析常量類型 if(!judge_content()) //判斷常量初始化是否有誤 goto end1; output(); //輸出結果（若沒有發現問題） end1: cout<<"The Analysis is finish!\nPlease input a string again!"<<endl; cout<<"\n-------------------------------------------------\n"<<endl; } return 0; }