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Why does comparing the result of scanf() with NULL generate a compiler warning?

由 佐手、 提交于 2019-12-25 18:42:33
问题 I'm writing in C and I need to read everything that arrives in input but I don't know how many characters I will receive. I wrote while (scanf("%c", &read) != NULL) but the compiler tells me: [Warning] comparison between pointer and integer , so what should I write instead? 回答1: Instead, of scanf("%c", &read) you may consider read = getc(stdin). Please, be aware that getc() / fgetc() return int . This allows to store any character as number in range [0, 255] as well as to return EOF (usually

Accessing an array java

由 删除回忆录丶 提交于 2019-12-25 18:21:24
问题 for(int i=0;i<dictionary.words.length;i++){ if(dictionary.words[i].length() <=maxWordlength){ count++; smallWordDictionary[i]=dictionary.words[i]; } } I used this code to store the strings from a dictionary array into an array containing strings with a shorter word length. I now want to pass this array alongside a random number to the following method( to create a randomly generated word ): randomWord(smallWordDictionary, outcome); When I use the following method: static void randomWord

Fragment returning Null context

由 我的梦境 提交于 2019-12-25 17:47:13
问题 I've been trying to fix this for the past 2 hours. Tried a lot of things. The Fragment seems to be passing a null context to my Adapter. I have tried to initialize the Context variable in onCreate and onCreateView and onActivityCreated. Same result. Here is my fragment: public class ActiveBookingsFragment extends Fragment { Context con; ArrayList<Booking> bookings; ListView activeBookings_lv; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); }

Ruby: Why is there a `nil` at the end of all the strings in my array?

由 折月煮酒 提交于 2019-12-25 16:57:00
问题 So I've written some code in Ruby to split a text file up into individual lines, then to group those lines based on a delimiter character. This output is then written to an array, which is passed to a method, which spits out HTML into a text file. I started running into problems when I tried to use gsub in different methods to replace placeholders in a HTML text file with values from the record array - Ruby kept telling me that I was passing in nil values. After trying to debug that part of

PowerShell two parameters either of them can be null but not both null

由 眉间皱痕 提交于 2019-12-25 16:42:22
问题 I'm wondering if this can be done at the parameter level rather in code: I have 2 parameter: $School and $Class Get-Students -School SchooName # Will give me all Students name in all classes in that School Get-Students -Class ClassName # Will give me all Students name in that Class across all schools Get-Students # Should return parameter level error. I tried to use following: function Get-Students{ param( [parameter(ParameterSetName="School no null")] [ValidateNotNullOrEmpty()] [string]

判定类型

由 自闭症网瘾萝莉.ら 提交于 2019-12-25 15:49:11
目前最精确的判定方法（不包括自定义类型） //2010.6.1更新 var is = function (obj,type) { return (type === "Null" && obj === null) || (type === "Undefined" && obj === void 0 ) || (type === "Number" && isFinite(obj)) || Object.prototype.toString.call(obj).slice(8,-1) === type; }, 用法如下： //***************示例一，判定数组与函数 var forEach = function(array,fn,bind){ if(is(array,"Array") && is(Array.forEach,"Function")){ array.forEach(fn,bind); }else{ for(var i=0,n=array.length;i<n;i++){ i in array && fn.call(bind,array[i],i,array) } } } //***************示例二，判定null var a = null alert(is(a,"Null")) //***************示例二，判定undefined var

Datatables - Json output - PostgreSQL - Returns null

由 会有一股神秘感。 提交于 2019-12-25 14:25:37
问题 I use datatables. I use it in conjunction with a Postgresql server. I want to take the data from the Postgresql server. I use the script found on: http://datatables.net/development/server-side/php_postgres The script works and creates the json file. The problem is that the values on the json file are null. This is what it returns: {"sEcho":1, "iTotalRecords":4, "iTotalDisplayRecords":4, "aaData":[[null,null,null], [null,null,null], [null,null,null], [null,null,null]]} Also what i don't

strlen sometimes equal to sizeof for null-terminated strings

由 我们两清 提交于 2019-12-25 14:01:07
问题 I know that strlen counts the number of characters up until (and excluding) the null character '\0' (or 0 ) and that sizeof gives the amount of space needed to store the string including the null character, but am confused with the output of my code. Question: I expect the result of strlen to be consistently 1 less than the result of sizeof because my strings are null-terminated, but it only seems to be the case for the string of length 4 and 8, excluding '\0' (i.e. the 3rd and 5th results

Select row if next a value in next row is null

由 ╄→гoц情女王★ 提交于 2019-12-25 11:58:17
问题 I need to know how to select a row if the next row has a null value for specific column. For example: Ind | Opt50 | Stat 44 | 1 | NR 45 | 1 | CL 46 | NULL | NULL 47 | 1 | IE 48 | NULL | NULL 49 | NULL | NULL 50 | 1 | NR 51 | 1 | IE 52 | 1 | CL 53 | 1 | IE 54 | NULL | NULL If Status is 'IE' and Option50 is NULL for the next record, then I need to return that next record. For the table above I need the query to find ind 47 and 53 and to return ind 48 and 54. Ind | Opt50 | Stat 48 | NULL | NULL

Searching for strings that are NULL terminated within a file where they are not NULL terminated

由 大兔子大兔子 提交于 2019-12-25 08:58:33
问题 I am writing a program that opens two files for reading: the first file contains 20 names which I store in an array of the form Names[0] = John\0 . The second file is a large text file that contains many occurences of each of the 20 names. I need my program to scan the entirity of the second file and each time it finds one of the names, a variable Count is incremented and so on the completion of the program, the total number of all the names appearing in the text is stored in Count . Here is
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