To access and use a variable or function dinamically, with Name from a String in JavaScript, just use the window object, with this syntax:
window['variable_name'] // For function window['function_name'](parameters)Here is some examples, see the explanations in code.
var vr_name = 'vr1'; // string with name of a variable var vr1 = 'coursesweb.net/'; // uses variable with name stored as string in vr_name // window[vr_name] /window['vr1'] is the value of vr1 var site = 'http://'+ window[vr_name]; // Test document.write(site); // https://coursesweb.net/
// object with strings with variable names
var vr_name = {'v1':'vr1', 'v2':'vr2'};
var vr1 = 'coursesweb.net/';
var vr2 = 'gamv.eu/';
// uses variable dinamically, with name stored as string in vr_name
var i = 2;
var site = 'https://'+ window[vr_name['v'+ i]];
// Test
document.write(site); // https://gamv.eu/
function f1(a, b) {
return a + b;
}
var f_name = 'f1'; // string with function name
// uses function with name stored as string in f_name
// window[f_name](parameters) calls the f1(parameters)
var sum = window[f_name](12, 23);
// Test
document.write(sum); // 35
object['method_name'](parameters).
// object with strings with method names
var methods = {'m1':'hi1', 'm2':'hi2'};
// object with two methods
var obj = {
'hi1': function(name) {
return 'Hello dear '+ name;
},
'hi2': function(name) {
return 'Hola '+ name;
}
};
// uses object method with name stored as string in methods
var hi = obj[methods['m1']]('ME');
// Test
document.write(hi); // Hello dear ME
<p>Web development courses: <em>CoursesWeb.net</em></p>
h3 {
padding: 2px 0.2em;
}// gets first Div with class="cls", and shows its content
var elm = document.querySelector("div.cls");
alert(elm.innerHTML);if(isset($_POST["field"])) {
echo $_POST["field"];
}