iOS 判断数组array中是否包含元素a，取出a在array中的下标

/////////1111111

    NSArray * arr = @[@"1",@"2",@"3",@"4",@"5"];
    //是否包含
    if ([arr containsObject:@"3"]) {
        
        NSInteger index = [arr indexOfObject:@"3"];
        NSLog(@"-1---%ld---",index);
    }
    
    //输出是  2
    


    //////////22222222

    if ([arr indexOfObject:@"5"] != NSNotFound) {
        
        NSInteger inde =[arr indexOfObject:@"5"] ;
        NSLog(@"-2---%ld----",inde);

    }else{
        
        NSLog(@"不存在");
    }
    
    
    //////22222---->>>>3333333
    
    NSInteger inde =[arr indexOfObject:@"5"];

    if (inde != NSNotFound) {
      
        NSLog(@"-2---%ld----",inde);
        
    }else{
        
        NSLog(@"不存在");
    }


///////44444 用for in 来判断