Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Looping
Search
John Nunemaker
PRO
September 24, 2009
Programming
0
14
Looping
John Nunemaker
PRO
September 24, 2009
Tweet
Share
More Decks by John Nunemaker
See All by John Nunemaker
Atom
jnunemaker
PRO
10
4.3k
MongoDB for Analytics
jnunemaker
PRO
11
950
Addicted to Stable
jnunemaker
PRO
32
2.6k
MongoDB for Analytics
jnunemaker
PRO
21
2.3k
MongoDB for Analytics
jnunemaker
PRO
16
30k
Why You Should Never Use an ORM
jnunemaker
PRO
59
9.5k
Why NoSQL?
jnunemaker
PRO
10
950
Don't Repeat Yourself, Repeat Others
jnunemaker
PRO
7
3.5k
I Have No Talent
jnunemaker
PRO
14
980
Other Decks in Programming
See All in Programming
Performance for Conversion! 分散トレーシングでボトルネックを 特定せよ
inetand
0
130
CloudflareのChat Agent Starter Kitで簡単!AIチャットボット構築
syumai
2
470
rage against annotate_predecessor
junk0612
0
160
複雑なドメインに挑む.pdf
yukisakai1225
5
1.1k
AIコーディングAgentとの向き合い方
eycjur
0
270
さようなら Date。 ようこそTemporal! 3年間先行利用して得られた知見の共有
8beeeaaat
3
1.4k
意外と簡単!?フロントエンドでパスキー認証を実現する WebAuthn
teamlab
PRO
2
720
Ruby Parser progress report 2025
yui_knk
1
430
Swift Updates - Learn Languages 2025
koher
2
470
AIでLINEスタンプを作ってみた
eycjur
1
230
@Environment(\.keyPath)那么好我不允许你们不知道! / atEnvironment keyPath is so good and you should know it!
lovee
0
110
アセットのコンパイルについて
ojun9
0
120
Featured
See All Featured
Gamification - CAS2011
davidbonilla
81
5.4k
Mobile First: as difficult as doing things right
swwweet
224
9.9k
Scaling GitHub
holman
463
140k
Practical Orchestrator
shlominoach
190
11k
Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]
tammyeverts
8
520
The Illustrated Children's Guide to Kubernetes
chrisshort
48
50k
Side Projects
sachag
455
43k
Balancing Empowerment & Direction
lara
3
620
Build The Right Thing And Hit Your Dates
maggiecrowley
37
2.9k
The Psychology of Web Performance [Beyond Tellerrand 2023]
tammyeverts
49
3k
Rebuilding a faster, lazier Slack
samanthasiow
83
9.2k
Bash Introduction
62gerente
615
210k
Transcript
loops executing code over and over again Thursday, September 24,
2009
Thursday, September 24, 2009
for loop loop a specified number of times; the only
loop you need to know http://www.w3schools.com/jS/js_loop_for.asp Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } before any loops Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } before each loop Thursday, September 24, 2009
for (var i=0; i < 5; i++) { // some
code to run } after each loop Thursday, September 24, 2009
for (var i=0; 0 < 5; i++) { // i
would be 0 } Thursday, September 24, 2009
for (var i=0; 1 < 5; i++) { // i
would be 1 } Thursday, September 24, 2009
for (var i=0; 2 < 5; i++) { // i
would be 2 } Thursday, September 24, 2009
for (var i=0; 3 < 5; i++) { // i
would be 3 } Thursday, September 24, 2009
for (var i=0; 4 < 5; i++) { // i
would be 4 } Thursday, September 24, 2009
for (var i=0; 5 < 5; i++) { // condition
false so this // would never happen } Thursday, September 24, 2009
for (var i=0; 5 < 5; i++) { // condition
false so this // would never happen } Thursday, September 24, 2009
var colors = ['red', 'green', 'blue']; for(var i=0; i <
colors.length; i++) { colors[i]; } Thursday, September 24, 2009
var colors = ['red', 'green', 'blue']; for(var i=0, length=colors.length; i
< length; i++) { colors[i]; } Thursday, September 24, 2009
var colors = ['red', 'green', 'blue']; var length = colors.length;
for(var i=0; i < length; i++) { colors[i]; } Thursday, September 24, 2009
while loop loop while a condition is true http://www.w3schools.com/JS/js_loop_while.asp Thursday,
September 24, 2009
var i = 0; while (i < 5) { //
some code to run i++; } Thursday, September 24, 2009
var i = 0; while (i < 5) { //
some code to run i++; } before each loop Thursday, September 24, 2009
var i = 0; while (0 < 5) { //
i would be 0 i++; // i would be 1 } Thursday, September 24, 2009
var i = 0; while (1 < 5) { //
i would be 1 i++; // i would be 2 } Thursday, September 24, 2009
var i = 0; while (2 < 5) { //
i would be 2 i++; // i would be 3 } Thursday, September 24, 2009
var i = 0; while (3 < 5) { //
i would be 3 i++; // i would be 4 } Thursday, September 24, 2009
var i = 0; while (4 < 5) { //
i would be 4 i++; // i would be 5 } Thursday, September 24, 2009
var i = 0; while (5 < 5) { //
condition is false so // this would never happen i++; } Thursday, September 24, 2009
var i = 0; while (5 < 5) { //
condition is false so // this would never happen i++; } Thursday, September 24, 2009
for..in loop loop through the properties of an object http://www.w3schools.com/jS/js_loop_for_in.asp
Thursday, September 24, 2009
for (property in object) { // some code here }
Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; person[property]; } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘name’ person[property]; // ‘John Nunemaker’ } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘age’ person[property]; // 27 } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘married’ person[property]; // true } Thursday, September 24, 2009
var person = { name: 'John Nunemaker', age: 27, married:
true, cat_owner: 'unfortunately' }; for (property in person) { property; // ‘cat_owner’ person[property]; // ‘unfortunately’ } Thursday, September 24, 2009
break break the current loop and continue with code after
loop if any http://www.w3schools.com/jS/js_break.asp Thursday, September 24, 2009
think “stop looping right now” Thursday, September 24, 2009
for (var i=0; i < 5; i++) { if (i
=== 2) { break; } i; } Thursday, September 24, 2009
for (var i=0; 0 < 5; i++) { if (0
=== 2) { // false break; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 0 < 5; i++) { if (0
=== 2) { // false break; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 1 < 5; i++) { if (1
=== 2) { // false break; } i; // 1 } Thursday, September 24, 2009
for (var i=0; 1 < 5; i++) { if (1
=== 2) { // false break; } i; // 1 } Thursday, September 24, 2009
for (var i=0; 2 < 5; i++) { if (2
=== 2) { // true break; // breaks out of loop } i; // never gets here } Thursday, September 24, 2009
for (var i=0; 2 < 5; i++) { if (2
=== 2) { // true break; // breaks out of loop } i; // never gets here } Thursday, September 24, 2009
most common use is switch statement, but good to know
it works elsewhere Thursday, September 24, 2009
continue break the current loop and continue with the next
value http://www.w3schools.com/jS/js_break.asp Thursday, September 24, 2009
think “skip current loop” Thursday, September 24, 2009
for (var i=0; i < 3; i++) { if (i
=== 1) { continue; } i; // comment } Thursday, September 24, 2009
for (var i=0; 0 < 3; i++) { if (0
=== 1) { // false continue; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 0 < 3; i++) { if (0
=== 1) { // false continue; } i; // 0 } Thursday, September 24, 2009
for (var i=0; 1 < 3; i++) { if (1
=== 1) { // true continue; } i; // never gets here } Thursday, September 24, 2009
for (var i=0; 1 < 3; i++) { if (1
=== 1) { // true continue; } i; // never gets here } Thursday, September 24, 2009
for (var i=0; 2 < 3; i++) { if (2
=== 1) { // false continue; } i; // 2 } Thursday, September 24, 2009
for (var i=0; 2 < 3; i++) { if (2
=== 1) { // false continue; } i; // 2 } Thursday, September 24, 2009
for (var i=0; 3 < 3; i++) { // never
gets here if (i === 1) { continue; } i; } Thursday, September 24, 2009
for (var i=0; 3 < 3; i++) { // never
gets here if (i === 1) { continue; } i; } Thursday, September 24, 2009
assignment04 http://teaching.johnnunemaker.com/capp-30550/sessions/looping/ Thursday, September 24, 2009