Declare a variable
use var keyword to declare a variable, var allow to redeclare a variable.
var x;
Initialisation of variable
x=100;
Print a variable
using document.write()
document.write(x)
using console.log()
console.log(x)
Multiple variable declaration
var x, y, z;
Multiple initialisation
x=y=z=100;
Concat variable with a string
document.write("x="+x);
Note: document.write() does not allow multiple statements without concat.
use of backtick (``)
document.write(`x=${x}`);