Basic Function

functionswap.js

function changeValue(a) {
    console.log('Value of a inside function before changing: ' + a);
    a = 10;
    console.log('Value of a inside function after changing: ' + a);
    return a;
}

var a = 100;
console.log('Value of a before changing function is applied: ' + a);
changeValue(a);
console.log('Value of a after changing function is applied: ' + a);