使用谓词与正则表达式判定字符串形式

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // 待判定的字符串
        NSString *str          = @"Hello World";
        // 正则表达式字符串
        NSString *regex        = @"^[a-zA-Z ]+$";
        // 谓词
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
        // 谓词求值
        BOOL isValid           = [predicate evaluateWithObject:str];
        
        NSLog(@"%@", isValid ? @"YES" : @"NO");
    }
    return 0;
}

YES