Question

对不起，我是swift的新手。我想用字符串计算目标字符。但我不知道该怎么做。对我有什么好的建议吗？谢谢。

let string = "hello\nNice to meet you.\nMy name is Leo.\n" //I want to get 3

Answer 1

如果您只想要换行字符，那么您可以对字符串的字符使用过滤器：

let string = "hello\nNice to meet you.\nMy name is Leo.\n"
let count = string.characters.filter { $0 == "\n" }.count
print(count)

按预期输出3。

Answer 2

另一种方法是使用import java.util.ArrayList; public class TestingJava { public ArrayList<Integer> plusOne(ArrayList<Integer> a) { // If vector has [1, 2, 3] // returned vector should be [1, 2, 4] // 123 + 1 = 124 int total = 0; // O(n) for(Integer i: a){ total = 10*total + i; } total += 1; int last_dig = total%10; a.set((a.size()-1), last_dig); // O(n**2) while (a.get(0) == 0){ a.remove(0); } return a; } public static void main(String[] args) { ArrayList<Integer> a1 = new ArrayList<>(); a1.add(0); a1.add(1); a1.add(2); a1.add(3); TestingJava c = new TestingJava(); System.out.println(c.plusOne(a1)); // Should output [1, 2, 4]. Should NOT output [0, 1, 2, 4] } }方法拆分行：

components(separatedBy

或多功能考虑各种换行符

let string = "hello\nNice to meet you.\nMy name is Leo.\n"
let lineCounter = string.components(separatedBy: "\n").count - 1

由于尾随换行符，结果为4.要忽略尾随的新行，您必须减少结果。

如何通过swift获取字符串中的换行频率

2 个答案: