Javascript-14-For Loops

For Loops

• For loop: for(initiation(optional),condition,increment(optional))

• var i = 2;
  len = cars.length;
  var text = "";
  for (; i < len; i++) { 
      text += cars[i] + "<br>";
  }
• If you omit statement 2, you must provide a break inside the loop. Otherwise the loop will never end. This will crash your browser.

• For in: for(variableName in objectname)

• var person = {fname:"John", lname:"Doe", age:25}; 
  var text = "";
  var x;
  for (x in person) {
      text += person[x];
  }

It is a common mistake, among new JavaScript developers, to believe that this code returns undefined:

It is true in many programming languages, but not true in JavaScript.

Example:

for (var i = 0; i < 10; i++) {// some code}
return i;

The code returns value of i as "10", though ideally it is out of the for loop. Thats how it is in javascript

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