``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142``` ```1 00:00:00,000 --> 00:00:03,290 >> DAVID J. MALAN: So that last program had a bug whereby it reported that 0 2 00:00:03,290 --> 00:00:07,220 is negative, even though technically 0 is neither positive nor negative. 3 00:00:07,220 --> 00:00:08,000 But not a problem. 4 00:00:08,000 --> 00:00:11,820 We can fix this bug by inserting another condition into our program. 5 00:00:11,820 --> 00:00:14,500 >> Specifically, at line 12 I'm going to hit Enter. 6 00:00:14,500 --> 00:00:19,560 And then add else if and equals equals 0, open curly 7 00:00:19,560 --> 00:00:21,900 brace, close curly brace. 8 00:00:21,900 --> 00:00:24,650 >> Now you'll notice that I said and typed equals equals as 9 00:00:24,650 --> 00:00:26,050 opposed to just equals. 10 00:00:26,050 --> 00:00:29,880 Now that's simply because C is already using a single equal sign as the 11 00:00:29,880 --> 00:00:33,630 so-called assignment operator and in order to assign a value from the right 12 00:00:33,630 --> 00:00:35,950 to a, say, variable on the left. 13 00:00:35,950 --> 00:00:39,700 But in this case, we actually want to test n for equality with 0. 14 00:00:39,700 --> 00:00:43,950 And to do that in C, you simply have to remember to use two equal signs. 15 00:00:43,950 --> 00:00:47,340 >> Well, if n does indeed equal equal 0, I'm going to print out 16 00:00:47,340 --> 00:00:48,730 the following instead. 17 00:00:48,730 --> 00:00:53,690 Print F, you picked 0. 18 00:00:53,690 --> 00:00:54,700 Save my file. 19 00:00:54,700 --> 00:00:59,090 And now let's compile this as conditions 1. 20 00:00:59,090 --> 00:01:02,670 >> Back at my blinking prompt, I'm going to run the program with dot slash, 21 00:01:02,670 --> 00:01:04,180 conditions 1. 22 00:01:04,180 --> 00:01:06,970 And let's do that same sanity check again as before. 23 00:01:06,970 --> 00:01:09,750 1 for my int, which is indeed positive. 24 00:01:09,750 --> 00:01:14,480 Let's rerun this as conditions 1 with a second input of, say, negative 1, 25 00:01:14,480 --> 00:01:16,180 which is indeed negative. 26 00:01:16,180 --> 00:01:18,060 >> Now let's test it with 0. 27 00:01:18,060 --> 00:01:19,575 dot slash, conditions 1. 28 00:01:19,575 --> 00:01:20,715 Enter. 29 00:01:20,715 --> 00:01:22,665 0 and-- 30 00:01:22,665 --> 00:01:23,435 phew. 31 00:01:23,435 --> 00:01:25,670 I indeed picked 0 this time. 32 00:01:25,670 --> 00:01:27,330 ```