Alternative to If-Else Statements or Better Approach

Alternative to if-else statements or better approach

Your collection names seems to have a pattern based on the filter fields, if that's the case this approach may work.

Object marketFilter = filter.getAllMarket();
Object cmtsFilter = filter.getAllCmts();
Object packageFilter = filter.getAllPackage();
Object nodeFilter = filter.getAllNodes();


if(marketFilter != null){
    query.addFilterField("_id.market", MongoQuEry.OP_IN, filter.getMarket());
}
.
.
. upto filter N

String collectionName = getCollectionName(marketFilter, ... filter N)

/* 
 create a function getCollectionName(filter1, ... filterN)   
  in this function you can generate collection name by checking which 
  filters are not null.
*/

NOTE :- This approach will work only if your collection names are based on the filters.

Alternative to if else statements or suggest best approach

It looks like you're implementing a search method for each possible combination of your search criteria. You shouldn't do it like that. Instead, the method filtering the elements should test each criterion:

public List<Element> search(List<Element> allElements, UserInputs criteria) {
    List<Element> acceptedElements = new ArrayList<>();
    for (Element e : allElements) {
        if (isAccepted(e, criteria)) {
            acceptedElements.add(e);
        }
    }
    return acceptedElements;
}

private boolean isAccepted(Element e, UserInputs criteria) {
    String firstName = criteria.getFirstName();
    if (isCriterionFilled(firstName) && !hasFirstName(e, firstName)) {
        return false;
    }

    String lastName = criteria.getLastName();
    if (isCriterionFilled(lastName) && !hasLastName(e, lastName)) {
        return false;
    }

    String phone = criteria.getPhone();
    if (isCriterionFilled(phone) && !hasPhone(e, phone)) {
        return false;
    }

    return true;
}

What is the better alternative for If else in implementing the logic in a program? | C#

Sum up and centralize the totaling operation in a separate method and check the state each of the Checkboxes while doing the sum:

public decimal TotalCosts()
{
    decimal total = 0.0m;

    if ({Oil Changed Checked})
       total += {Oil Cost};

    if ({Transmission checked})
       total += {Transmission total};

    if ({Repair Clutch})         
       total += {Clutch Cost}; // Maybe call a separate method ClutchTotal()?

     ... { Do this for all check boxes }

    return total;
}

Don't attempt to individually add things together for disparate operations (as you did with the both_var = radiatorRush_var + transmissionFlush_var; , that is your confusion.

Finite State Machine

I mentioned a finite state machine logic which is useful in organizing any code.

Think of a vending machine, it has to take all different types of coins as well as dollar bills and it has certain states before it can provide product. By mapping out all states and then centralizing the code to handle each state, that will go far in make the code bug free and maintainable.

If one adds a dime into the machine, the state goes from Welcome into summing up the current coins and dollars but not providing the product. That state is true until total > cost, then the Vend state is hit which distributes the product. It doesn't go back to the Welcome state until it finishes a final step of provide any monies if overpayment.

By setting up states one can organize one's code to handle all situations as you are seeing in your app.

A better alternative to using a long series of if/else if statements in C?

Use a loop. You'll also need an array of the minimum data value for each grade. Here's some untested code as an example:

for (int i = 9; i >= 0; i--)
{
    if (data[y] >= minDataValueForGrade[i])
    {
        grades[i]++;
        break;
    }
}

It's short, easy to read, and makes it really easy to change the values that correspond to each grade.

Is there an alternative to using IF / ELSE statements

? : operator is exactly that, a "cleaner" if-else

http://msdn.microsoft.com/en-us/library/ty67wk28.aspx

classify = (input < 0) ? "negative" : "positive";

There are also switch statements for larger combinations:

http://www.w3schools.com/js/js_switch.asp

switch(n)
{
case 1:
  execute code block 1
  break;
case 2:
  execute code block 2
  break;
default:
  code to be executed if n is different from case 1 and 2
}

Polymorphism is an abstract concept, not a way to write a statement. It's the practice of creating a method/function/class/etc where type is at least SOMEWHAT ambiguous. So the same method could return a result if fed, say, an integer for parameter 1, the same as if you were to feed an array into the same parameter.

Alternative to multiple if else statements in JavaScript?

You can use an object as a map:

function getCode(input) {    var inputMap = {      "Corporation": "534",      "LLC": "535",      "LLP": "536",      "Partnership": "537",      "Sole Proprietorship": "538",      "Limited Partnership": "539"    };
    var defaultCode = "540";        return inputMap[input] || defaultCode;}
console.log(getCode("LLP"));console.log(getCode("Lorem Ipsum"));

LinkedHashMap<String, String> mapping = new LinkedHashMap<>();
mapping.put("unsupported", "unsupported");
mapping.put("final_result", "final_result");
// ... etc

for (Map.Entry<String, String> entry : mapping.entrySet()) {
  if (str.contains(entry.getKey()) {
    mailType = entry.getValue();
    break;
  }
}

LinkedHashMap<String, LinkedHashMap<String, String>> outerMapping =
    new LinkedHashMap<>();
outerMapping.put("template", mapping);
outerMapping.put("properties", someOtherMapping);

for (Map.Entry<String, LinkedHashMap<String, String>> outerEntry : outerMapping.entrySet()) {
  if (str.contains(outerEntry.getKey()) {
    // Apply the iteration above, using outerEntry.getValue().
  }
}