ios - 从字符串中删除空格和多行？

Question

我有一个字符串，像这样:

"  \n assddd\n\n\n\n\n adjf fff dd \n\n\n\n       tjhfhdf \n      "

我想要的结果是:

"assddd\nadjffffdd\ntjhfhdf". 

1:我使用 trimmingCharacters 删除了开头和结尾:

let title = "  \n assddd\n\n\n\n\n adjf fff dd \n\n\n\n       tjhfhdf \n".trimmingCharacters(in: .whitespacesAndNewlines)

2: 去除空格

let result = title.replacingOccurrences(of: " ", with: "")

但是，如何保留字符之间的第一个“\n”并删除其他“\n”？

Answer 1

你可以找到两个或多个连续的换行符一个正则表达式，并用一个换行符替换它们特点。示例:

let s1 = "AA\n\nBB\nCC\n\n\n\n\nDD"
let s2 = s1.replacingOccurrences(of: "\\n{2,}", with: "\n", options: .regularExpression)

print(s1.debugDescription) // "AA\n\nBB\nCC\n\n\n\n\nDD"
print(s2.debugDescription) // "AA\nBB\nCC\nDD"

适用于您的情况:

let title = "  \n assddd\n\n\n\n\n adjf fff dd \n\n\n\n       tjhfhdf \n      "

let result = title.trimmingCharacters(in: .whitespacesAndNewlines)
    .replacingOccurrences(of: " ", with: "")
    .replacingOccurrences(of: "\\n{2,}", with: "\n", options: .regularExpression)

print(result.debugDescription) // "assddd\nadjffffdd\ntjhfhdf"