Iteration & Conditionals Lesson Notes

iteration-conditionals.md

Iteration & Conditionals

Objectives

• Use if / else if / if to write conditional code
• Identify the syntax of standard for loops
• Write for loops
• Write while loops
• Loop over an array
• Loop over an object

Guiding Questions

• What will the following code snippets print out?

  if (2 > 1) {
    console.log('A');
  } else {
    console.log('B');
  }

  Your answer...

  if (2 > 1 && 5 <= 3) {
    console.log('C');
  } else {
    console.log('D');
  }

  Your answer...

  if (7 % 2 === 0 || Number.isInteger(3.4)) {
    console.log('E');
  } else if (6 <= Math.floor(5.8)) {
    console.log('F');
  } else {
    console.log('G');
  }

  Your answer...

  Practice

  Complete the challenges in this lesson: https://learn.galvanize.com/cohorts/650/units/7294/content_files/82809

• What is a for loop used for in javascript?

  Your answer...

• Looking at the following example, idetify the 5 main parts of the for loop:

  1. keyword
  2. initial step
  3. condition
  4. increment step
  5. body
  

  for(var i = 0; i < 5; i++) {
    console.log(i)
  }

  Your answer...

• What is a while loop used for in javascript? When would you use a while loop instead of a for loop?

  Your answer...

  Practice

  Complete the challenges in this lesson: https://learn.galvanize.com/cohorts/650/units/7294/content_files/82807

Looping over Arrays and Objects

Resources

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration