Splitting a string into different variables

[reshmidoudou]

a string contains an equation and I have to break the string into integers and other variables :

example of the string is "2 + 3 = 5"

I have tried to use substr but it does not work as I can have "120 - 30 = 90" so the integers are of no fixed length.

How can I do that, please help!

[zahidkhan]

a string contains an equation and I have to break the string into integers and other variables :

example of the string is "2 + 3 = 5"

I have tried to use substr but it does not work as I can have "120 - 30 = 90" so the integers are of no fixed length.

How can I do that, please help!

Hi you can use sscanf
like this
const char* p = "100-200=300";
int i,j,k;
sscanf(p,"%d-%d=%d",&i,&j,&k);

But make it sure that there should not be any space in your string expression

[anushhprabu]

if(isdigit(*expr_Ite) || isDot(*expr_Ite)) // for numbers and DOT
{
while(isdigit(*expr_Ite) || isDot(*expr_Ite))
{
if(isDot(*expr_Ite)) // Flag to check the occurrence of DOT
{
Flag=1;
}
else
{
Temp1*=10;
Temp1+=((*expr_Ite)-48);//-48 is used to get the numbers.. ASCII value for 0 is 48... 9 is 57
}
if(Flag==1) ++Temp2; // to count number of digits after DOT
++expr_Ite;
loop++;
}//while(isDot() || is dot())
while(Temp2>1) { Temp1=Temp1/10; Temp2--; } // to manipulate the integer into float value
Value.push(Temp1);
}

[vermarajeev]

int main(int argc, char** argv[])
{
    string str;
    string variable;
    string integers;
    cout<<"Enter the string"<<endl;
    cin>>str;
 
    int j=0;
    bool flag = false;
    for(int i=0; i<strlen(str.data()); ++i)
    {
        if(!isdigit(str[i]))
        {
            variable.push_back(str[i]);                
            flag = true;
        }
        else
        {            
            integers.push_back(str[i]);    
        }
        if(flag)
        {
           integers.push_back('\n');    
           variable.push_back('\n');    
           flag = false;
        }
    }    
    cout<<"variable:"<<variable<<endl;
    cout<<"integers:"<<integers<<endl;
 
    return 0;
}

[reshmidoudou]

Thanks for the code, guys. Another question, I have to test the maximum input done on the screen, let me explain when keying the input after the 5th input the pgm should display a message like invalid input.

example : I type the equation

2 + 3 = 5 (input = 5 )

but if I type

2 + 3 = 5 + 0 (input more than 5)

how do I do the test since the coding is like that@

int var1, var2 , result;
string op, eq;

cin >> var1 >> op >> var2 >> eq >> result;

I am stuck who can help pls?