Question

我想在foreach数组的最后一项中添加某些字符串。

该程序完美无缺。给定“pending”数组中的项目，它应该将out值附加到挂起值的最后一项：

String a = out + "-" + rptdate + "-";
for (String pn : pending) {
    //checks if total value + pending length value is less than 160
    if (a.length() + pn.length() < 160) { // < to leave room for the comma as well
        if (a.length() != 0) {
            if (a.length() != 14) {
                a += ",";
            }
        }

        a += pn;
    } else {
        resultingStrings.add(a);
        a = pn;
        Log.d("messages", a);
    }
}
resultingStrings.add(a);
for (String r : resultingStrings) {
    sendSMS(r);
}

Answer 1

尝试简单的代码

int size = pending.size();
int index = 0;
for (String pn : pending) {
    if(index == size - 1){
      // it is last foreach => add your last string here
    }
    index++;    
    ...
}

希望这个帮助

Answer 2

你也可以这样做，

for(int i = 0; i < array.length; i++) {

    if(i = (array.length - 1)) {

        //this is the last element in the array
    }
}

Answer 3

如果你需要做的就是抓住Collection的最后一个元素并为它添加一些文本，那么这应该可行。

String out = "Some value";    
int lastIndex = pending.getSize() -1; // < 0 indexed
String lastItem = pending.get(lastIndex)
String newLastItem = lastItem + out; // < String concatenation

但是从你的片段我不认为这是你的追求，因为如果我们删除一些神奇的数字并纠正缩进，并对你试图做什么做出一些假设

String a = out + "-" + rptdate + "-";
int prefixLength = a.length();
for (String pn : pending) {
    //checks if total value + pending length value is less than 160
    if (a.length() + pn.length() < MAX_LENGTH) { // < to leave room for the comma as well
        if (a.length() > prefixLength) {
            a += ",";
        }

        a += pn;
    } else {
        // have string longer than max length, so save and start a new sms.
        resultingStrings.add(a);
        Log.d("messages", a); // < log a before you overwrite it.
        a = pn;
    }
}

// DO YOU WANT TO APPEND out AS A SUFFIX TO a HERE ???
// a += out;
// but if so youll want to consider the case if a is now > MAX_LENGTH

resultingStrings.add(a); // add the last string

// send all composed strings
for (String r : resultingStrings) {
    sendSMS(r);
}

我正在挑选你相对较新的编码，所以我建议你首先从一些伪代码开始，然后在你的代码中成为注释。始终保持代码格式良好，以便匹配缩进，并为变量和常量使用描述性名称。

如何在最后一个foreach项中添加字符串？

3 个答案: