JavaScript Closures

Transcript

1. for ( var i=0; i<5; i++ ) { // Wait i seconds then print // the number of seconds waited for each i }
2. for ( var i=0; i<5; i++ ) { // Wait i seconds then print // the number of seconds waited for each i }
3. JavaScript Closures Get comfortable leanmachine.se ▪ hello@leanmachine.se ▪ 2013-09-06
4. Server JavaScript allows you to refer to variables that were defined outside of the current function Functions can refer to variables defined in outer functions, even a!er those functions have returned Closures can update the values of outer variables Three rules of closures
5. console.log(generateUnique()); console.log(generateUnique()); console.log(generateUnique());
6. What does the scope chain look like?
7. It can be inspected in browser dev tools
8. Bonus The with-keyword
9. leanmachine.se ▪ hello@leanmachine.se ▪ 2013-09-06