iphone - 使用 NSPredicate 将以数字或符号开头的字符串过滤到 NSArray

Question

如何使用 NSPredicate 将以数字或符号开头的字符串过滤到 NSArray。

例子:

array = {"John", "Mary", "Aroldo", "1John", "+Mary"}

to newArray = {"1John," "+Mary"}

Answer 1

这里有 4 种方法。所有示例都使用否定字符类。你的请求是过滤掉数字和符号，但你也可以说你想过滤掉以非字母字符开头的单词。

- (void)testFilterArray0
{
    predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", @"[^a-zA-Z].*"];
    filtered = [unfiltered filteredArrayUsingPredicate:predicate];
    STAssertTrue([filtered isEqualToArray:expected], nil);
}

- (void)testFilteredArray1
{
    predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", @"[^\\p{L}].*"];
    filtered = [unfiltered filteredArrayUsingPredicate:predicate];
    STAssertTrue([filtered isEqualToArray:expected], nil);
}

- (void)testFilteredArray2
{
    predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", @"[^\\p{Letter}].*"];
    filtered = [unfiltered filteredArrayUsingPredicate:predicate];
    STAssertTrue([filtered isEqualToArray:expected], nil);
}

- (void)testFilteredArray3
{
    predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", @"[^\\p{General_Category=Letter}].*"];
    filtered = [unfiltered filteredArrayUsingPredicate:predicate];
    STAssertTrue([filtered isEqualToArray:expected], nil);
}