null

来源： https://stackoverflow.com/questions/42948228/removing-null-characters-from-big-files-in-windows

来源： https://stackoverflow.com/questions/42948228/removing-null-characters-from-big-files-in-windows

来源： https://stackoverflow.com/questions/42948228/removing-null-characters-from-big-files-in-windows

来源： https://stackoverflow.com/questions/53163648/jackson-yaml-serialize-null-as-empty-value

来源： https://stackoverflow.com/questions/53163648/jackson-yaml-serialize-null-as-empty-value

问题 Every query has a final row with an asterisk beside it and null values for every field? Why does this show up? I cant seem to find an explanation for it. Even putting a WHERE clause doesnt seem to get rid of it. Is this only happening to the MySQL implementation alone? 回答1: It is for inserting a new row, you enter the values there. 回答2: Are you sure it's not just the data entry row. Usually when viewing the table data in something like Workbench or SQLYog, it will display the rows of data,

问题 Every query has a final row with an asterisk beside it and null values for every field? Why does this show up? I cant seem to find an explanation for it. Even putting a WHERE clause doesnt seem to get rid of it. Is this only happening to the MySQL implementation alone? 回答1: It is for inserting a new row, you enter the values there. 回答2: Are you sure it's not just the data entry row. Usually when viewing the table data in something like Workbench or SQLYog, it will display the rows of data,

问题 Suppose I have an array of objects of type Foo in C++: Foo array[10]; In Java, I can set an object in this array to null simply by: array[0] = null //the first one How can I do this in C++? 回答1: Use pointers instead: Foo *array[10]; // Dynamically allocate the memory for the element in `array[0]` array[0] = new Foo(); array[1] = new Foo(); ... // Make sure you free the memory before setting // the array element to point to null delete array[1]; delete array[0]; // Set the pointer in `array[0]

问题 Suppose I have an array of objects of type Foo in C++: Foo array[10]; In Java, I can set an object in this array to null simply by: array[0] = null //the first one How can I do this in C++? 回答1: Use pointers instead: Foo *array[10]; // Dynamically allocate the memory for the element in `array[0]` array[0] = new Foo(); array[1] = new Foo(); ... // Make sure you free the memory before setting // the array element to point to null delete array[1]; delete array[0]; // Set the pointer in `array[0]

问题 Getting this error at the moment: Uncaught TypeError: Cannot read property 'value' of null I call this in my render function below: <input type="submit" className="nameInput" id="name" value="cp-dev1" onClick={this.writeData}/> I also have tried calling it in here componentWillMount: function(){ var name = document.getElementById('name').value; }, How can I get the id of an input text field and read that value and ensure it is not null? I think the DOM is loading after I try to read the