Tutorial by Examples: bool

The BOOL type is used for boolean values in Objective-C. It has two values, YES, and NO, in contrast to the more common "true" and "false". Its behavior is straightforward and identical to the C language's. BOOL areEqual = (1 == 1); // areEqual is YES BOOL areNotEqual = !ar...

you can custom class below one private final String PROTOCOL_CONTENT_TYPE = String.format("application/json; charset=%s", PROTOCOL_CHARSET); public BooleanRequest(int method, String url, String requestBody, Response.Listener<Boolean> listener, Response.ErrorListener errorList...

There is no format specifier to print boolean type using NSLog. One way to print boolean value is to convert it to a string. BOOL boolValue = YES; NSLog(@"Bool value %@", boolValue ? @"YES" : @"NO"); Output: 2016-07-30 22:53:18.269 Test[4445:64129] Bool value YES ...

CREATE TABLE all_binary_types( c_boolean boolean, c_binary binary ); Sample data: insert into all_binary_types values (0,1234); insert into all_binary_types values (1,4321); Note: For boolean, internally it stored as true or false. For binary, it will store base64 encoded value....

for numbers, a zero value evaluates to false, non zero to true int i = 0 ... if (i) print "some ${i}" else print "nothing" will print "nothing"

a string (including GStrings) evaluates to true if not null and not empty, false if null or empty def s = '' ... if (s) println 's is not empty' else println 's is empty' will print: 's is empty'

Collections and Maps evaluates to true if not null and not empty and false if null or empty /* an empty map example*/ def userInfo = [:] if (!userInfo) userInfo << ['user': 'Groot', 'species' : 'unknown' ] will add user: 'Groot' , species : 'unknown' as default userInfo since the u...

a null object reference evaluates to false, a non null reference to true, but for for strings, collections, iterators and enumerations it also takes into account the size. def m = null if (!m) println "empty" else println "${m}" will print "empty" de...

Sometimes it may be useful to have a specific asBoolean definition in your own program for some kind of objects. /** an oversimplified robot controller */ class RunController { def complexCondition int position = 0 def asBoolean() { return complexCondition(this...

An integer type whose value can be either true or false. bool is_even(int x) { return x%2 == 0; } const bool b = is_even(47); // false

For booleans, SQLite uses integers 0 and 1: sqlite> SELECT 2 + 2 = 4; 1 sqlite> SELECT 'a' = 'b'; 0 sqlite> SELECT typeof('a' = 'b'); integer > CREATE TABLE Users ( Name, IsAdmin ); > INSERT INTO Users VALUES ('root', 1); > INSERT INTO Users VALUES ('john', 0); > S...

$true and $false are two variables that represent logical TRUE and FALSE. Note that you have to specify the dollar sign as the first character (which is different from C#). $boolExpr = "abc".Length -eq 3 # length of "abc" is 3, hence $boolExpr will be True if($boolExpr -eq $tr...

Sometimes we need to perform basic operations like hide/show view based on single value, for that single variable we cannot create model or it is not good practice to create model for that. DataBinding supports basic datatypes to perform those oprations. <layout xmlns:android="http://schema...

Considering that most debuggers are not aware of #define macros, but can check enum constants, it may be desirable to do something like this: #if __STDC_VERSION__ < 199900L typedef enum { false, true } bool; /* Modern C code might expect these to be macros. */ # ifndef bool # define bool bo...

BooleanQuery is used to combine other queries. They can be combined using three BooleanClause.Occur parameters: BooleanClause.Occur.MUST - The subquery must be matched. BooleanClause.Occur.SHOULD - The subquery may not be matched, but will be scored more highly if it is. If there are no MUST...

Sometimes a new Java programmer will write code like this: public void check(boolean ok) { if (ok == true) { // Note 'ok == true' System.out.println("It is OK"); } } An experienced programmer would spot that as being clumsy and want to rewrite it as: publ...

Use the double negation syntax to check for truthiness of values. All values correspond to a boolean, irrespective of their type. irb(main):001:0> !!1234 => true irb(main):002:0> !!"Hello, world!" (irb):2: warning: string literal in condition => true irb(main):003:0> !...

A boolean array can be created manually by using dtype=bool when creating the array. Values other than 0, None, False or empty strings are considered True. import numpy as np bool_arr = np.array([1, 0.5, 0, None, 'a', '', True, False], dtype=bool) print(bool_arr) # output: [ True True False ...

const options = require("commander"); options .option("-v, --verbose") .parse(process.argv); if (options.verbose){ console.log("Let's make some noise!"); }

When only a single argument is supplied to numpy's where function it returns the indices of the input array (the condition) that evaluate as true (same behaviour as numpy.nonzero). This can be used to extract the indices of an array that satisfy a given condition. import numpy as np a = np.arang...