字符串连接C问题

Question

我试图将多个整数变量连接成一个字符串，这样我就可以将它作为csv发送到另一个程序。但是，我无法获得字符串。你能仔细检查这段代码以确保它是正确的吗？

这适用于拥有自己的String库的Spark / Particle设备。唯一类型的＆＃34;字符串＆＃34;我可以返回一个字符串类型，这就是我这样做的原因......

void updatePresetVar(void) {
    String s = String();
    int integer = getGrind1;
    String integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getDuration1;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getWeight1;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getGrind2;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getDuration2;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getWeight2;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getGrind3;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getDuration3;
    integer_string = String(integer);
    s = String(s + integer_string);
    s = String(s + ",");

    integer = getWeight3;
    integer_string = String(integer);
    s = String(s + integer_string);

    presets = String(s);
}

编辑：有时我得到以下输出：

�[，或@ [，或P