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Validate that a string is a positive integer
...ue);
},
false
);
test("1", true);
test("1.23", false);
test("1234567890123", true);
test("1234567890123.1", false);
test("0123", false); // false because we don't handle leading 0s
test(" 123 ", false); // false because we don't handle whitespace
<label>
String:
<inp...
What is a 'semantic predicate' in ANTLR?
...) throws Exception {
ANTLRStringStream in = new ANTLRStringStream("123, 456, 7 , 89");
NumbersLexer lexer = new NumbersLexer(in);
CommonTokenStream tokens = new CommonTokenStream(lexer);
NumbersParser parser = new NumbersParser(tokens);
parser.parse();
}...
App Inventor 2 DynamicComponents 拓展：动态创建AI2组件对象 · App Inventor 2 中文网
...可以动态删除一行布局，截图如下：
代码块如下：
源码下载：
dynamic_component_demo.aia
FAQ
如何设置块的属性？
有两种选择，效果一样：
SetProperty
或 Any Component
如何删除所...
Items in JSON object are out of order using “json.dumps”?
...this we get:
>>> import OrderedDict
>>> unordered={"id":123,"name":"a_name","timezone":"tz"}
>>> ordered = OrderedDict.OrderedDict( [("id",123), ("name","a_name"), ("timezone","tz")] )
>>> e = OrderedJsonEncoder()
>>> print e.encode( unordered )
{"timezo...
How can I call controller/view helper methods from the console in Ruby on Rails?
...the helper object:
$ ./script/console
>> helper.number_to_currency('123.45')
=> "R$ 123,45"
If you want to use a helper that's not included by default (say, because you removed helper :all from ApplicationController), just include the helper.
>> include BogusHelper
>> helper...
How to convert JSON data into a Python object
...ace
data = '{"name": "John Smith", "hometown": {"name": "New York", "id": 123}}'
# Parse JSON into an object with attributes corresponding to dict keys.
x = json.loads(data, object_hook=lambda d: SimpleNamespace(**d))
print(x.name, x.hometown.name, x.hometown.id)
OLD ANSWER (Python2)
In Python2, ...
what is faster: in_array or isset? [closed]
...e, you can check out the compiled version of your script:
echo isset($arr[123])
compiled vars: !0 = $arr
line # * op fetch ext return operands
-----------------------------------------------------------------------------
1 0 > ZEND_ISSET_ISEMPTY_...
What is Normalisation (or Normalization)?
...ase that usually contains family members
id, name, address
214 Mr. Chris 123 Main St.
317 Mrs. Chris 123 Main St.
could be normalized as
id name familyID
214 Mr. Chris 27
317 Mrs. Chris 27
and a family table
ID, address
27 123 Main St.
Near-Complete normalization (BCNF) is usually not used...
PHP convert XML to JSON
...ult in key pointing to array of elements: <list><item><a>123</a><a>456</a></item><item><a>123</a></item></list> -> {"item":[{"a":["123","456"]},{"a":"123"}]}. A solution at php.net by ratfactor solves that issue by always sto...
What is “export default” in javascript?
...ello() {
console.log("Modul: Saying hello!");
}
export let variable = 123;
modul2.js
export function hello2() {
console.log("Module2: Saying hello for the second time!");
}
export let variable2 = 456;
modul3.js
export default function hello3() {
console.log("Module3: Saying hello...