Java——》累加求和：1~100

累加求和：計算1+2+3+...+100=5050

public class Test {
    public static void main(String[] args) {
        int param = 100;
        System.out.println("for循環：" + forMethod(param));
        System.out.println("while循環：" + whileMethod(param));
        System.out.println("遞歸：" + dgMethod(param));
    }

    static int forMethod(int param) {
        int sum = 0;
        for (int i = 1; i <= param; i++) {
            sum = sum + i;
        }
        return sum;
    }

    static int whileMethod(int param) {
        int sum = 0;
        int i = 1;
        while (i <= param) {
            sum = sum + i;
            i++;
        }
        return sum;
    }

    static int dgMethod(int param) {
        int sum = 0;
        if (param == 1)
            return 1;
        else
            sum = param + dgMethod(param - 1);
        return sum;
    }
}