Objective-C中NSArray和NSMutableArray的基本用法

 /*---------------------NSArray---------------------------*/        //创建数组        NSArray *array1 = [NSArray arrayWithObject:@"1"];        NSArray *array2 = [NSArray arrayWithObjects:@"1",@"2",@"3", nil];        NSArray *array3 = [NSArray arrayWithArray:array2];        NSLog(@"array1 = %@",array1);        NSLog(@"array2 = %@",array2);        NSLog(@"array3 = %@",array3);                //获取数组内数据个数        int count = [array2 count];        NSLog(@"array2 size is %d",count);                //访问数组内的数据        NSString *str1 = [array2 objectAtIndex:0];        NSLog(@"array2 first content is %@",str1);                //数组中插入数据   返回新的数组        NSArray *array4 = [array3 arrayByAddingObject:@"4"];        NSLog(@"array4 = %@",array4);                //数组内的数据以制定字符连接        NSString *str2 = [array4 componentsJoinedByString:@","];        NSLog(@"str2 = %@",str2);                //判断数组中是否包含某对象        BOOL b1 = [array4 containsObject:@"4"];        BOOL b2 = [array4 containsObject:@"5"];        NSLog(@"b1 = %d,b2 = %d",b1,b2);                //取数组内制定对象的索引        int index = [array4 indexOfObject:@"4"];        NSLog(@"index = %d",index);                NSString *str3 = [array4 lastObject];        NSLog(@"array4 last object is %@",str3);                /*-----------------------可变数组NSMutableArray-----------------------------------------*/        //初始化数组 指定数组长度   但可变        NSMutableArray *mArray1 = [NSMutableArray arrayWithCapacity:5];                //向数组中添加元素        [mArray1 addObject:@"aaaa"];        [mArray1 addObject:@"cccc"];        NSLog(@"mArray1 = %@",mArray1);                //向指定位置插入元素        [mArray1 insertObject:@"bbbb" atIndex:1];        [mArray1 insertObject:@"dddd" atIndex:[mArray1 count]];        [mArray1 insertObject:@"eeee" atIndex:[mArray1 count]];        NSLog(@"mArray1 = %@",mArray1);                //移除元素        [mArray1 removeObject:@"eeee"];        NSLog(@"mArray1 = %@",mArray1);        [mArray1 removeObjectAtIndex:[mArray1 count]-1];        NSLog(@"mArray1 = %@",mArray1);        NSArray *array5 = [NSArray arrayWithObjects:@"bbbb",@"cccc", nil];        [mArray1 removeObjectsInArray:array5];        NSLog(@"mArray1 = %@",mArray1);                //向数组内插入数组        NSMutableArray *mArray2 = [NSMutableArray arrayWithObjects:@"aaaa",@"aaaa", nil];        [mArray2 addObject:@"bbbb"];        NSLog(@"mArray2 = %@",mArray2);        [mArray2 addObjectsFromArray:array4];        NSLog(@"mArray2 = %@",mArray2);                //替换元素        [mArray2 replaceObjectAtIndex:[mArray2 count]-1 withObject:@"5"];        NSLog(@"mArray2 = %@",mArray2);                //遍历数组  常规方法:性能较低        NSArray *array6 = [NSArray arrayWithObjects:@"a",@"b",@"c",@"d",@"e", nil];        int len = [array6 count];        for (int i=0; i<len; i++) {            NSString *value = [array6 objectAtIndex:i];            NSLog(@"array6 %d content is %@",i,value);        }                //枚举遍历  相当于java中的增强for循环        for (NSString *string in array6) {            NSLog(@"array6 content is %@",string);        }                NSLog(@"-----------------------");                //当不确定数组元素类型时        for(id string in array6){            NSLog(@"array6 content is %@",string);        }