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How to get the sizes of the tables of a MySQL database?
...
Size of all tables:
Suppose your database or TABLE_SCHEMA name is "news_alert". Then this query will show the size of all tables in the database.
SELECT
TABLE_NAME AS `Table`,
ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024),2) AS `Size (MB)`
FROM
information_schema.TABLES
WHERE
TABLE_...
Detecting an undefined object property
...ty is the special value undefined, is:
if(o.myProperty === undefined) {
alert("myProperty value is the special value `undefined`");
}
To check if an object does not actually have such a property, and will therefore return undefined by default when you try and access it:
if(!o.hasOwnProperty('m...
Android Calling JavaScript functions in WebView
...ntion. This call: final Object a = new Object(); callJavaScript(mBrowser, "alert", 1, true, "abc", a); will yield to SyntaxError with Unexpected token which is not surprising when you will look at the generated js call: javascript:try{alert(,,'abc',,)}catch(error){console.error(error.message);}
...
What is the exact difference between currentTarget property and target property in javascript
...px;
border: 1px solid blue;
}
</style>
<form onclick="alert('form')">FORM
<div onclick="alert('div')">DIV
<p onclick="alert('p')">P</p>
</div>
</form>
If click on the P tag in above code then you will get three alert,and if yo...
Check if a JavaScript string is a URL
...
new URL('javascript:alert(23)')
– blade091
Oct 2 '17 at 15:47
6
...
When is null or undefined used in JavaScript? [duplicate]
...s scenarios:
You declare a variable with var but never set it.
var foo;
alert(foo); //undefined.
You attempt to access a property on an object you've never set.
var foo = {};
alert(foo.bar); //undefined
You attempt to access an argument that was never provided.
function myFunction (foo) {
...
Add new value to an existing array in JavaScript [duplicate]
...ay
// ---
arr = []; // empty array
// ---
arr = new Array(3);
alert(arr.length); // 3
alert(arr[0]); // undefined
// ---
arr = [3];
alert(arr.length); // 1
alert(arr[0]); // 3
Pushing to the array:
arr = [3]; // arr == [3]
arr[1] = 4; // arr == [3, 4]
arr[2] = 5; // arr...
JavaScript curry: what are the practical applications?
...rototype.split.partial(/,\s*/);
var results = "John, Resig, Boston".csv();
alert( (results[1] == "Resig") + " The text values were split properly" );
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AngularJS - pass function to directive
...pe.color1 = "color";
$scope.updateFn = function(msg) {
alert(msg);
}
});
app.directive('test', function() {
return {
restrict: 'E',
scope: {
color1: '=',
updateFn: '&'
},
// object is passed while making the cal...
How can I use jQuery in Greasemonkey scripts in Google Chrome?
...serscript
function main() {
// Note, jQ replaces $ to avoid conflicts.
alert("There are " + jQ('a').length + " links on this page.");
}
// load jQuery and execute the main function
addJQuery(main);
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