The left operand '>' is the value for garbage

Question

When I build and change my application, I get a warning below.

"Left operand '>' is garbage value" on this line isTrue = (newLength> 20)? NO YES;

What is the problem here. Thanks for any help

 (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSUInteger newLength;
    BOOL isTrue;
    if(textField == txtFirstName){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue = (newLength > 20) ? NO : YES;
    }
    if(textField == txtLastName){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue = (newLength > 20) ? NO : YES;
    }
    if(textField == txtEmail){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue =  (newLength > 100) ? NO : YES;
    }
    if(textField == txtCompanyName){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue =  (newLength > 30) ? NO : YES;
    }
    if(textField == txtPassword){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue =  (newLength > 30) ? NO : YES;
    }
    if(textField == txtRe_EnterPassword){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue =  (newLength > 30) ? NO : YES;
    }
    if(textField == txtZipCode){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue =  (newLength > 20) ? NO : YES;
    }
    if(textField == txtCountry){
        newLength = [textField.text length] + [string length] - range.length;
        //isTrue =  (newLength > 30) ? NO : YES;
    }
    isTrue = (newLength > 20) ? NO : YES;

    return isTrue;
}

Answer 1

The problem occurs when all if conditions fail, i.e. if textFieldnot included in the kit that you expect from it.

In this case, it is newLengthnever assigned and will be a random garbage value. Although this is likely to "never happen," the static analyzer does not know this.

newLength, , , .

Answer 2

, " " "". newLength , , . .

Answer 3

. , .

(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSUInteger newLength = 0;
    BOOL isTrue = false;

    if(textField == txtFirstName){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue = (newLength > 20) ? NO : YES;
    }
    else if(textField == txtLastName){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue = (newLength > 20) ? NO : YES;
    }
    else if(textField == txtEmail){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue =  (newLength > 100) ? NO : YES;
    }
    else if(textField == txtCompanyName){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue =  (newLength > 30) ? NO : YES;
    }
    else if(textField == txtPassword){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue =  (newLength > 30) ? NO : YES;
    }
    else if(textField == txtRe_EnterPassword){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue =  (newLength > 30) ? NO : YES;
    }
    else if(textField == txtZipCode){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue =  (newLength > 20) ? NO : YES;
    }
    else if(textField == txtCountry){
        newLength = [textField.text length] + [string length] - range.length;
        isTrue =  (newLength > 30) ? NO : YES;
    }
    else {
        isTrue = (newLength > 20) ? NO : YES;
    }

    return isTrue;
}

Answer 4

, ( ) if . . , .

else ifs , NSAssert.

Answer 5

Try [a compare: b] returns -1 if a <b, 0 if a == b and 1 if a> b.

isTrue = ([newLength compare: 20] == 1)? NO YES;