ios-過濾字符串的開頭是數字或符號

過濾字符串的開頭是數字或符號

怎麼樣對字符串的開頭是數字或是符號進行過濾，然後給帶NSPredicate的NSArray。

舉個例子：

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

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

最佳回答：

有四種方法可以實現。每個方法都用了否定字符類，你的需求是要求數字或者符號，也就是非字母character。

- (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);
}