Syntax, Cont'd...

Console

var foo = 10; 
var bar = 20; 

if (foo < bar ) {
//console.log("foo is less than bar");
//console.log("and here's a second message");
//console.log("and here's a third message");
//console.log(foo);
//console.log(foo,bar);
//console.debug("foo is less than bar");
//console.info("foo is less than bar");
//console.warn("foo is less than bar");
console.error("foo is less than bar");

}

Loops

// When we realize rather quickly how valuable code-reuse, even within a script is to the developer. 

// Logic Example:

for every link {
    statement one
    statment two
}

// I. WHILE LOOP (The Most Basic Kind of Loop):

var a = 1;

while ( a < 10 ) { // is a less than 10? yes thats true, continue to the next line...
    console.log(a);
    };  // <-- WARNING! INFINITE LOOP!
    
// Thus, to fix the infinity of this loop, we increment the a variable by one with each iteration of the loop:

while ( a < 10 ) {
    console.log(a); 
    a++; 
    }
    
// II. The "DO..WHILE LOOP"
// "WHILE LOOPS are much more common than these, DO...WHILE LOOPS, b/c it's always considered best practice to check the condition
// ...before entering the loop. And it's more readable that way too!

var a = 100;

do{
    console.log(a); // the block will always iterate at least once! Even if the var a is set to 100, it loops at least once before checking the condition.
    a++;
} while ( a < 10 );


// In many loops a pattern emerges:

// Take this WHILE LOOP:

var i = 1;          // <-- Set up the Index...

while ( i < 10 ) {  // <-- Check the Condition...
    // do stuff
    // do stuff
    // do stuff
    i++;            // <-- Increment the Index/Counter...
}

// No matter how many statements are inside the loop we always have the basic skeletal structure of the loop as above...

//  III. The "FOR LOOP" :

//  Set up an "Index" or a "Counter" variable.
//  There is another, more professional and correct term for the i var, check crockford's 2011 lecture video.

// Now, because there are always the three main features inherent in any loop:
//  1. Set up the Index..
//  2. Check the Condition...
//  3. Increment the Index/Counter...

// There is a shorter way to create this type of loop, The "FOR LOOP"

for ( var i = 1; i < 10; i++ ) {
    // do stuff
    // do stuff
    // do stuff 
    // etc...
}

//  Another way of explaining the above:
// for (setupindex; checkCondition; incrementCounter)



//  IV. BREAK:
// BREAK Jumps us out of the loop. 

// For Example:

for ( var i = 1; i < 5000; i++ ) {
    // do stuff
    // do stuff
    if ( i == 101 ) {
        break;
    }
    // do stuff
}
// break jumps out of the loop


//  V. CONTINUE:
//  
for ( var i = 1; i < 5000; i++ ) {
    // do stuff
    // do stuff
    if (i % 5 == 0) {
        continue; // done with this iteration
    }
    // do second set of stuff
    // do second set of stuff
}