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问题 I want to change my current function to return empty JSON list, currently it returns nil . This is my current code: func (s *Service) projectsGet(c *gin.Context) { var projects []*models.Project user := getUser(c) pag := models.NewPagination(c) ps, err := s.db.ProjectsGet(user.ID, &pag) if err != nil { apiError(c, http.StatusInternalServerError, err) return } projects = ps c.JSON(http.StatusOK, projects) } I want it to return [] , how I can do it? 回答1: A nil slice encodes to a null JSON

问题 At this moment I have a big table in Excel that I would like to use with dynamic dropdown (cascade options). Depending on the selection you do on the first dropdown, then in the next cell, you should have a filtered drop down menu. Also, any option is unique for the main category selected. The first thing I did was to take the columns I need and pivot them so it looks something similar to this (C are the column names and V are the values. Since any option is unique for any category, I have

问题 At this moment I have a big table in Excel that I would like to use with dynamic dropdown (cascade options). Depending on the selection you do on the first dropdown, then in the next cell, you should have a filtered drop down menu. Also, any option is unique for the main category selected. The first thing I did was to take the columns I need and pivot them so it looks something similar to this (C are the column names and V are the values. Since any option is unique for any category, I have

问题 At this moment I have a big table in Excel that I would like to use with dynamic dropdown (cascade options). Depending on the selection you do on the first dropdown, then in the next cell, you should have a filtered drop down menu. Also, any option is unique for the main category selected. The first thing I did was to take the columns I need and pivot them so it looks something similar to this (C are the column names and V are the values. Since any option is unique for any category, I have

问题 I have some code and when I run it produces an error, saying: NoSuchMethod: the method 'XYZ' was called on null What does that mean and how do I fix it? 回答1: Why do I get this error? Example As a real world comparison, what just happened is this conversation: Hey, how much gas is left in the tank of the car? What are you talking about, we don't have a car. That is exactly what is happening in your program. You wanted to call a function like _car.getGasLevel(); but there is no car , the

问题 I have some code and when I run it produces an error, saying: NoSuchMethod: the method 'XYZ' was called on null What does that mean and how do I fix it? 回答1: Why do I get this error? Example As a real world comparison, what just happened is this conversation: Hey, how much gas is left in the tank of the car? What are you talking about, we don't have a car. That is exactly what is happening in your program. You wanted to call a function like _car.getGasLevel(); but there is no car , the

问题 This question already has answers here : How to get a null terminated string from a C# string? (4 answers) Closed 2 years ago . Hello StackOverflowers, I read somewhere that C# string are not null terminated. M'fine ! But I'd like to know if the method : byte[] myBytes = Encoding.ASCII.GetBytes(myString); add a null termination character to the end of the array or if I must do it manually ? (the C system which will use this array does need it). If manual, I guess the way would be : byte[]

问题 This question already has answers here : How to get a null terminated string from a C# string? (4 answers) Closed 2 years ago . Hello StackOverflowers, I read somewhere that C# string are not null terminated. M'fine ! But I'd like to know if the method : byte[] myBytes = Encoding.ASCII.GetBytes(myString); add a null termination character to the end of the array or if I must do it manually ? (the C system which will use this array does need it). If manual, I guess the way would be : byte[]

问题 If you create temp tables using "insert into" in SQL Server it uses the first insert to determine whether a column accepts null value or not. if the first insert has null value the column become nullable otherwise it will be non-nullable. Is there a way to create temp tables using "insert into" to accept null values? Example This works without any problem Select 'one' as a , null as b into #temp insert into #temp Select 'two' as a , 500 as b However this throws "Cannot insert the value NULL

问题 This question already has answers here : What is the difference between a variable, object, and reference? [duplicate] (5 answers) Closed 5 years ago . What happens if I do: Object obj = new Object(); obj = null; Does it remove the object from memory, or clear just the reference? More formally, consider the code: Object obj = new Object(); Object temp = obj; obj = null; Why is temp still not null ? Shouldn't it have been removed from memory? 回答1: In your first example: obj -------> |OBJECT|