typescript template extends code example

Example 1: extend generics in functions typescript

interface Lengthwise {
    length: number;
}

function loggingIdentity<T extends Lengthwise>(arg: T): T {
    console.log(arg.length);  // Now we know it has a .length property, so no more error
    return arg;
}

Example 2: how to make a generic variable in javascript

var x = 1;
var y = 1;
if (x == y) {
  x = x + 1
}