println

println vs System.out.println in Scala

由 我怕爱的太早我们不能终老 提交于 2019-11-30 05:35:32
I always thought that Predef.println was merely a shortcut for System.out.println , but apparently I am mistaken, since it doesn't seem to use System.out at all. Why is that so? And how can I do the "redirecting" of System.out below in Scala? scala> val baos = new java.io.ByteArrayOutputStream baos: java.io.ByteArrayOutputStream = scala> val ps = new java.io.PrintStream(baos) ps: java.io.PrintStream = java.io.PrintStream@6c5ac4 scala> System.setOut(ps) scala> println("hello") hello scala> new String(baos.toByteArray) res2: java.lang.String = "" scala> System.out.println("hello") scala> new

Difference between println and print in Swift

由 守給你的承諾、 提交于 2019-11-30 03:13:58
问题 The use of println and print in Swift both print to the console. But the only difference between them seems to be that println returns to the next line whereas print will not. For example: println("hello world") println("another world") will output the following two lines: hello world another world while: print("hello") print("world") outputs only one line: helloworld The print seems to be more like the traditional printf in C. The Swift documentation states that println is the equivalent to

Why doesn't a character increment in System.out.println()?

由 本秂侑毒 提交于 2019-11-29 18:55:27
char char1 = 'a'; System.out.println(char1); //prints char 1 System.out.println(char1+1); //prints char 1 System.out.println(char1++); //prints char 1 System.out.println(char1+=1); //prints incremented char1 char1 += 1; System.out.println(char1); //prints incremented char1 In the above, why doesn't (char1+1) or (char++) print the incremented character but theother two do? First, I'm assuming that because you say the increment in System.out.println works, that you have really specified: char char1 = 'a'; EDIT In response to the change of the question ( char1+1; => char1 += 1; ) I see the issue.

Why doesn't println! work in Rust unit tests?

由 余生颓废 提交于 2019-11-29 18:49:46
I've implemented the following method and unit test: use std::fs::File; use std::path::Path; use std::io::prelude::*; fn read_file(path: &Path) { let mut file = File::open(path).unwrap(); let mut contents = String::new(); file.read_to_string(&mut contents).unwrap(); println!("{}", contents); } #[test] fn test_read_file() { let path = &Path::new("/etc/hosts"); println!("{:?}", path); read_file(path); } I run the unit test this way: rustc --test app.rs; ./app I could also run this with cargo test I get a message back saying the test passed but the println! is never displayed on screen. Why not?

Java printing a String containing an integer

由 杀马特。学长 韩版系。学妹 提交于 2019-11-29 17:53:03
问题 I have a doubt which follows. public static void main(String[] args) throws IOException{ int number=1; System.out.println("M"+number+1); } Output: M11 But I want to get it printed M2 instead of M11. I couldn't number++ as the variable is involved with a for loop, which gives me different result if I do so and couldn't print it using another print statement, as the output format changes. Requesting you to help me how to print it properly. 回答1: Try this: System.out.printf("M%d%n", number+1);

Is it possible to print text that can be edited by the user (for console programs)?

由 六眼飞鱼酱① 提交于 2019-11-29 15:36:03
Say I allow the user to edit something, like the phone number in an Address Book (actually, that's exactly what I'm doing). Is there something that I can add to println that will allow me to insert a variable to display as fully editable text? The assignment that I'm doing this for doesn't actually call for this, but I think it would be cool to have. I'm looking on Google but can't find anything, then again I don't really know what I'm looking for and whether or not I have the correct terms in mind ... No, not using only what Java provides in the framework. Editing some text would require to

println vs System.out.println in Scala

由 你。 提交于 2019-11-29 05:52:57
问题 I always thought that Predef.println was merely a shortcut for System.out.println , but apparently I am mistaken, since it doesn't seem to use System.out at all. Why is that so? And how can I do the "redirecting" of System.out below in Scala? scala> val baos = new java.io.ByteArrayOutputStream baos: java.io.ByteArrayOutputStream = scala> val ps = new java.io.PrintStream(baos) ps: java.io.PrintStream = java.io.PrintStream@6c5ac4 scala> System.setOut(ps) scala> println("hello") hello scala> new

java.lang.NullPointerException: println needs a message

由 早过忘川 提交于 2019-11-29 05:30:26
I get the errror: java.lang.NullPointerException: println needs a message when I call this method: lst_info = new HashMap<String, String>(); SystemDatabaseHandler db = new SystemDatabaseHandler(getApplicationContext()); lst_info = db.getLstInfo(sql_id); SystemDatabaseHandler: public HashMap<String , String> getLstInfo(int id){ HashMap<String , String> lst_temp; lst_temp = new HashMap<String , String>(); String selectQuery = "SELECT * FROM dkr_lst_lst WHERE lst_id = " + id; SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(selectQuery, null); if (cursor.moveToFirst())

Why doesn't println! work in Rust unit tests?

由 元气小坏坏 提交于 2019-11-28 13:48:56
问题 I've implemented the following method and unit test: use std::fs::File; use std::path::Path; use std::io::prelude::*; fn read_file(path: &Path) { let mut file = File::open(path).unwrap(); let mut contents = String::new(); file.read_to_string(&mut contents).unwrap(); println!("{}", contents); } #[test] fn test_read_file() { let path = &Path::new("/etc/hosts"); println!("{:?}", path); read_file(path); } I run the unit test this way: rustc --test app.rs; ./app I could also run this with cargo

Why doesn't a character increment in System.out.println()?

由 强颜欢笑 提交于 2019-11-28 13:04:56
问题 char char1 = 'a'; System.out.println(char1); //prints char 1 System.out.println(char1+1); //prints char 1 System.out.println(char1++); //prints char 1 System.out.println(char1+=1); //prints incremented char1 char1 += 1; System.out.println(char1); //prints incremented char1 In the above, why doesn't (char1+1) or (char++) print the incremented character but theother two do? 回答1: First, I'm assuming that because you say the increment in System.out.println works, that you have really specified:
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