使用正则表达式在NSString中查找/替换子字符串

时间:2012-03-12 04:18:16

标签: objective-c ios regex ios5

我想使用正则表达式来查找正则表达式模式的每个实例。我的字符串中的&*;并将其删除,因此返回值是没有任何匹配项的原始字符串。也想使用相同的函数来匹配单词之间的多个空格,而是使用单个空格。找不到这样的功能。

示例输入字符串

NSString *str = @"123 &1245; Ross Test  12";

返回值应为

123 Ross Test 12

如果符合此模式的任何内容"&*或多个空格,并将其替换为@"";

2 个答案:

答案 0 :(得分:157)

NSString *string = @"123 &1245; Ross Test 12";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"&[^;]*;" options:NSRegularExpressionCaseInsensitive error:&error];
NSString *modifiedString = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:@""];
NSLog(@"%@", modifiedString);

答案 1 :(得分:12)

字符串在字符串扩展名

中使用正则表达式替换代码

<强>目标C

@implementation NSString(RegularExpression)

- (NSString *)replacingWithPattern:(NSString *)pattern withTemplate:(NSString *)withTemplate error:(NSError **)error {
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:error];
    return [regex stringByReplacingMatchesInString:self
                                           options:0
                                             range:NSMakeRange(0, self.length)
                                      withTemplate:withTemplate];
}

@end

决心

NSString *string = @"123 &1245; Ross Test  12";
// remove all matches string
NSString *result = [string replacingWithPattern:@"&[\\d]+?;" withTemplate:@"" error:nil];
// result = "123  Ross Test  12"

或更多

NSString *string = @"123 +   456";
// swap number
NSString *result = [string replacingWithPattern:@"([\\d]+)[ \\+]+([\\d]+)" withTemplate:@"$2 + $1" error:nil];
// result = 456 + 123

<强> Swift2

extension String {
    func replacing(pattern: String, withTemplate: String) throws -> String {
        let regex = try NSRegularExpression(pattern: pattern, options: .CaseInsensitive)
        return regex.stringByReplacingMatchesInString(self, options: [], range: NSRange(0..<self.utf16.count), withTemplate: withTemplate)
    }
}

<强> Swift3

extension String {
    func replacing(pattern: String, withTemplate: String) throws -> String {
        let regex = try RegularExpression(pattern: pattern, options: .caseInsensitive)
        return regex.stringByReplacingMatches(in: self, options: [], range: NSRange(0..<self.utf16.count), withTemplate: withTemplate)
    }
}

使用

var string = "1!I 2\"want 3#to 4$remove 5%all 6&digit and a char right after 7'from 8(string"
do {
    let result = try string.replacing("[\\d]+.", withTemplate: "")
} catch {
    // error
}
// result = "I want to remove all digit and a char right after from string"