Question

我想为NSRange中的每个组获得NSString，以空格分隔。

我目前有这个：

self.statement1String = [NSString stringWithFormat:@"??? = n1 + n2 + n3 + n4"];

for (NSString *component in [self.statement1String componentsSeparatedByString:@" "])
{
        NSRange range=[self.statement1String rangeOfString:component];
        NSLog(@"range is %@ for string %@", [NSValue valueWithRange:range], component);
}

打印出来

2014-11-12 17:19:00.011[3606:758370] range is NSRange: {0, 3} for string ???
2014-11-12 17:19:00.012[3606:758370] range is NSRange: {4, 1} for string =
2014-11-12 17:19:00.012[3606:758370] range is NSRange: {6, 2} for string n1
2014-11-12 17:19:00.013[3606:758370] range is NSRange: {9, 1} for string +
2014-11-12 17:19:00.013[3606:758370] range is NSRange: {11, 2} for string n2
2014-11-12 17:19:00.014[3606:758370] range is NSRange: {9, 1} for string +
2014-11-12 17:19:00.015[3606:758370] range is NSRange: {16, 2} for string n3
2014-11-12 17:19:00.015[3606:758370] range is NSRange: {9, 1} for string +
2014-11-12 17:19:00.015[3606:758370] range is NSRange: {21, 2} for string n4

我得到了相同的范围＆＃39; +＆＃39;在每次迭代中。我怎样才能确保我得到下一个＆＃39; +＆＃39;登录for循环？

Answer 1

您可以使用-rangeOfString:options:range:，将包含最后一个范围结尾的范围传递给字符串的结尾。

但是，这是一项更适合NSScanner的工作。

Answer 2

改为使用rangeOfString:options:range:。

self.statement1String = @"??? = n1 + n2 + n3 + n4";

NSInteger start = 0;
for (NSString *component in [self.statement1String componentsSeparatedByString:@" "]) {
    NSRange checkRange = NSMakeRange(start, self.statementString.length - start);
    NSRange range = [self.statement1String rangeOfString:component options:0 range:checkRange];
    NSLog(@"range is %@ for string %@", NSStringFromRange(range), component);
    start = range.location + range.length;
}

rangeOfString：始终为重复出现的字符返回相同的范围

2 个答案: