Question

我不明白这种方式的运作方式。我想从字符串列表中创建一个字符串数组。我计算列表中的字符串数，然后想要创建这些字符串的数组。我正在做一些测试并想出了这段代码：

string *newOrder;

int numNodes;

numNodes = alphaTree.numNodes();

newOrder = new string [numNodes];

newOrder[0] = "This is";
newOrder[1] = "a test";
newOrder[2] = "To see";
newOrder[3] = "If this";
newOrder[4] = "will work";

结果是newOrder就像是一个单独的字符串数组，其vaule为“This is”。我做错了什么？

Answer 1

检查numNodes = alphaTree.numNodes（）;正在返回所需的大小。

以下是一段正确的代码，分配5个字符串，然后分配。

newOrder = new string [5];
newOrder[0] = "This is";
newOrder[1] = "a test";
newOrder[2] = "To see";
newOrder[3] = "If this";
newOrder[4] = "will work";

如果执行以下语句：

cout << newOrder[2] << endl;

这将打印：要查看

Answer 2

using std::string;
using std::vector;

// from an initializer_list
vector<string> newOrder1 = {
    "This is",
    "a test",
    "To see",
    "If this",
    "will work",
};

// as a sequence of appends
// often used in a loop if an iterator is not applicable
vector<string> newOrder2;
newOrder2.push_back("This is");
newOrder2.push_back("a test");
newOrder2.push_back("To see");
newOrder2.push_back("If this");
newOrder2.push_back("will work");

// from an iterator-pair over any standards-compliant container
vector<string> newOrder3(alphaTree.begin(), alphaTree.end());

如何创建一个新的字符串数组

2 个答案: