C++ If Else If Not Working Properly

else part of the if else statement is not working

Your ifs/elses are not exhaustive. For instance, if a > b and c > a is not covered: inside the if (a>b), you only consider if (a > c), and if this condition is false, you do nothing (meaning, there is no else).

You seem to be under the impression that the final else (which prints "c is greatest") should be executed after each if that has no else. However, this is not how C works: this else is only executed if the condition of the if that precedes it is false. The fixed version of your first attempt is thus:

if(a>b){
    if(a>c){
        printf("a is greatest");
    } else{
        printf("c is greatest");
    }
}
else if(b>a){
    if(b>c){
        printf("b is greatest");
    } else{
        printf("c is greatest");
    }
}
else{
    printf("c is greatest");
}

However, the second version (with the &&) is clearer in my opinion.

Finally, when you remove the braces after if(b>a) (your 3rd version), the final else is associated with the if that precedes it, which is if(b>c) rather than if(b>a) (unlike when the braces are present). Your indentation is misleading, and should have been:

else if(b>a)
    if(b>c){
        printf("b is greatest");
    }
else {
    printf("c is greatest");
}

The same thing holds for your 4th version, which should be read as:

if(a>b)
    if(a>c)
        printf("a is greatest");
    else if(b>a)
        if(b>c)
            printf("b is greatest");
        else
            printf("c is greatest");

Notice how if(b>a) can never be true since it is inside the body of if(a>b).

Additionally, you never consider that some or all numbers could be equal. Without the broader context, we can't know if this can happen, but if it can happen, then you should probably take that case into account.

C++ if/else if statement not working correctly

cin >> input;

does not read whitespaces. You need to use std::getline.

getline(cin, input);

C++ if else if not working properly

Instead of this if(ID =="A"||"a"){, you should write if(ID =="A"|| ID == "a"){ because your statements: if(ID =="A"||"a"){ means if (ID is "A" or the ascii of "a"). The ascii of "a" is bigger than 0, that means it will be read as true value in the if statement. That's why your statement will be equal with if(ID =="A"|| true){ which is why only this statement will be executed.

`else if` condition not properly working in my program in c

You are assigning a value to gen

else if ((gen == 'M' && y_o_s >= 10 && qual == 0) || 
  (gen = 'M' && y_o_s < 10 && qual == 1))
       ^

So when you get to your next line gen is no longer what you expect.

else if (gen == 'M' && y_o_s < 10 && qual == 0)
             ^^

And then improve the code with SparKots suggestions.

Else condition not working even tho there is no error

The expression in the if statement

 else if(1<Number_Of_People<=6){

may be equivalently rewritten like

 else if( ( 1 < Number_Of_People ) <=6 ){

The relational operator < yields either 0 or 1 depending on whether the expression with the relational operator is logically false or true.

Thus the result of the subexpression ( 1 < Number_Of_People ) either equal to 0 or 1 in any case is less than 6.

So this if statement will be always evaluated if the preceding if statement will be skipped.

You need to rewrite the above if operator like

else if( ( 1 < Number_Of_People ) && ( Number_Of_People <= 6 ) ){

c: last loop in if elseif else is not working

I can't figure out why it won't go again in first "if", after in last
"else" ("Introduceti d sau n! "), I write 'n'. The 'd' is working fine
and going back to "else if".

Because of your while loop condition(while(decizie != 'n')). Loop will execute as long as you give anything but n as input. It won't go in the first if as you're giving n as the input.

C If statements not working

Prior to the commenting, each of the last three aaa/bbb/ccc if statements was nested within the previous such if statement. Thus, when if (aaa == bbb && aaa != ccc) tested as false, all the rest of the code up to the line of close braces was skipped.

In other words, what it really did was this:

    if (aaa == bbb && aaa != ccc) {
        int r = rand() % 2 + 1;
        printf("aRANDOM2 = %d\n",r);
        if (r == 1) {aaa = (aaa + 1);}
        if (r == 2) {bbb = (bbb + 1);}
            if (aaa == ccc && aaa != bbb) {
            int r = rand() % 2 + 1;
            printf("bRANDOM2 = %d\n",r);
            if (r == 1) {aaa = (aaa + 1);}
            if (r == 2) {ccc = (ccc + 1);}
            if (ccc == bbb && aaa != ccc) {
                int r = rand() % 2 + 1;
                printf("cRANDOM2 = %d\n",r);
                if (r == 1) {ccc = (ccc + 1);}
                if (r == 2) {bbb = (bbb + 1);}
                if (aaa == bbb && bbb == ccc) {
                    int r = rand() % 3 + 1;
                    printf("RANDOM3 = %d\n",r);
                    if (r == 1) {aaa = (aaa + 1);}
                    if (r == 2) {bbb = (bbb + 1);}
                    if (r == 3) {ccc = (ccc + 1);}
                }
            }
        }
    }
}

Probably what you want to do is to move three of the close braces to the end of their respective blocks, like this:

    if (aaa == bbb && aaa != ccc) {
        int r = rand() % 2 + 1;
        printf("aRANDOM2 = %d\n",r);
        if (r == 1) {aaa = (aaa + 1);}
        if (r == 2) {bbb = (bbb + 1);}
    }
    if (aaa == ccc && aaa != bbb) {
        int r = rand() % 2 + 1;
        printf("bRANDOM2 = %d\n",r);
        if (r == 1) {aaa = (aaa + 1);}
        if (r == 2) {ccc = (ccc + 1);}
    }
    if (ccc == bbb && aaa != ccc) {
        int r = rand() % 2 + 1;
        printf("cRANDOM2 = %d\n",r);
        if (r == 1) {ccc = (ccc + 1);}
        if (r == 2) {bbb = (bbb + 1);}
    }
    if (aaa == bbb && bbb == ccc) {
        int r = rand() % 3 + 1;
        printf("RANDOM3 = %d\n",r);
        if (r == 1) {aaa = (aaa + 1);}
        if (r == 2) {bbb = (bbb + 1);}
        if (r == 3) {ccc = (ccc + 1);}
    }
}