org.apache.poi.ss.formula.atp.Ifs Maven / Gradle / Ivy

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package org.apache.poi.ss.formula.atp;

import org.apache.poi.ss.formula.OperationEvaluationContext;
import org.apache.poi.ss.formula.eval.BoolEval;
import org.apache.poi.ss.formula.eval.ErrorEval;
import org.apache.poi.ss.formula.eval.ValueEval;
import org.apache.poi.ss.formula.functions.FreeRefFunction;

/**
 * Implementation of 'Analysis Toolpak' Excel function IFS()

 * 
 * The IFS function checks whether one or more conditions are met and returns a value that corresponds to the first TRUE condition.
 * IFS can take the place of multiple nested IF statements, and is much easier to read with multiple conditions.
 * 
 * Syntax

 * IFS(IFS([Something is True1, Value if True1, [Something is True2, Value if True2],…[Something is True127, Value if True127]))
 *
 * @author Pieter Degraeuwe
 */
final class Ifs implements FreeRefFunction {

    public static final FreeRefFunction instance = new Ifs();

    private Ifs() {
        // enforce singleton
    }

    public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec) {
        if (args.length % 2 != 0) {
            return ErrorEval.VALUE_INVALID;
        }

        for (int i = 0; i < args.length; i = i + 2) {
            BoolEval logicalTest = (BoolEval) args[i];
            if (logicalTest.getBooleanValue()) {
                return args[i + 1];
            }
        }

        return ErrorEval.NA;
    }

}