过滤字符串的开头是数字或符号

有四种方法可以实现。每个方法都用了否定字符类，你的需求是要求数字或者符号，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);
}