JavaScript Concepts

function-hoisiting.js

log(); 
var log = function(msg) {
    alert(msg);
}

/*
* in this case log function is a expression type and log varibale will be hoisted at the top 
* and initialized with undefined therefore, we will get 
* Uncaught TypeError: log is not a function
*/


// in below example log function will be called since all of the function declarations are hoinsted at the top before runing code. 
log();
function log(msg) {
    alert(msg);
}