## Why Loops End ## Lisa Lippincott No. 1 The heat death of the universe  ## Will this loop ever end? Yes! Execution increases bf/p128_6.jpg) Loops that end Loops that don't end Loops that are required to end Loops that are not required to end Loops that are required to end —___ while for goto Loops that are not required goto_unbounded Loops that are required to end and have a clearly explained local reason to end Loops that are required to end but have no clearly explained local reason to end Loops that are not required

• 4.6. Logical operators • 5. Conditionals 5.1. if 5.2. switch 5.3. Ternary conditional • 6. Loops o 6.1. for-in o 6.2. while o 6.3. repeat-while o 6.4. continue and break • 7. Comments • 8. // true a > b // false a <= b // true #### 4.5. Range operators Range operators are used in loops. They allow us to define a range: 0...3 //4 times 0...<3 //3 times 0...count //"count" shorter than an if statement, and sometimes it might make more sense to use it. ### 6. Loops #### 6.1. for-in for-in loops can be used to iterate a specific amount of times, using a range operator: for index

5. Conditionals • 5.1. if • 5.2. switch • 6. Loops • 6.1. For loops • 6.2. While loops • 6.3. Do while loops • 6.4. Breaking out of a loop using break • 7. Arrays handle all the other cases */ break; } ### 6. Loops C offers us three ways to perform a loop: for loops, while loops and do while loops. They all allow you to iterate over arrays, but with a few differences. Let's see them in details. #### 6.1. For loops The first, and probably most common, way to perform a loop is for loops. Using the for keyword we can define the rules of the loop up

refers to all those things that control the flow of a program - conditionals (i.e. if/elif/else), for-loops, as well as things like macros and blocks. With the default syntax, control structures appear inside corresponding loop did not break. Since Jinja loops cannot break anyway, a slightly different behavior of the else keyword was chosen. It is also possible to use loops recursively. This is useful if you are are dealing with recursive data such as sitemap or RDFa. To use loops recursively, you basically have to add the recursive modifier to the loop definition and call the loop variable with the new iterable

StreamAgg_17 root 1 → #7)->Column#5 → loops:2 → /A → -IndexReader_18 root 1 → loops:2,rpc num:1,rpc time:10.884355ms,proc keys:25007 206 → Bytes 857819905217 table:t,index:idx( → a),range:[-inf,50000),keep order:false 25007 time:11ms,loops → :25 → /A → N/A +--- → If you are conducting a performance test, | 1 | root | time → :170.08572ms, loops:2 | → funcs:count(Column#5)->Column#3 | 372 Bytes | N/A | | -TableReader_17 | 1.00 | 1 | root | time → :170.080369ms, loops:2,rpc num:1,rpc time:17.023347ms,proc

→ #7)->Column#5 1 time:10.931505ms, → loops:2 372 Bytes N → /A | | -IndexReader_18 root 1 index:StreamAgg_9 → time:10.927685ms, → loops:2,rpc num:1,rpc time:10.884355ms,proc keys:25007 → Column#7 1 time:11ms,loops → :25 N/A → N/A | | -IndexScan_16 cop 31281.857819905217 table:t,index:idx( → a),range:[-inf,50000),keep order:false 25007 time:11ms,loops → :25 N/A N → | 1 | root | time → :170.08572ms, loops:2 | → funcs:count(Column#5)->Column#3 | 372 Bytes | N/A | | -TableReader_17 | 1.00 | 1 | root | time → :170.080369ms, loops:2,rpc num:1,rpc time:17.023347ms,proc

"bonjour" ## CLASSES AND OBJECTS Instead of going through all the rest of Ruby’s syntax - its types, loops, modules and so on (but fear not, we’ll come back to those soon) - let’s move rapidly on to take a executes when you run the program. Don't worry about the syntax of this; we'll be looking at loops in a future lesson. I've added this loop so that you can easily run the different bits of code (a,b,c,d) in multiarr print("a=#{a}, b=#{b}, c=#{c}, d=#{d}\n") end Iterators and for loops The code inside a for loop is executed for each element in some expression. The syntax can be summarized

Expressions 79 9.2 Conditional Evaluation 80 9.3 Short-Circuit Evaluation 83 9.4 Repeated Evaluation: Loops 85 9.5 Exception Handling 88 Built-in Exceptions 88 The throw function 89 Errors 90 The try/catch Scope of Variables 93 Scope constructs 93 10.1 Global Scope 94 10.2 Local Scope 94 Let Blocks 101 Loops and Comprehensions 102 10.3 Constants 103 11 Types 105 11.1 Type Declarations 106 11.2 Abstract Types managing worker processes 274 25.3 Data Movement 275 25.4 Global variables 276 25.5 Parallel Map and Loops 277 25.6 Remote References and AbstractChannels 279 25.7 Channels and RemoteChannels 279 Remote References

Expressions 79 9.2 Conditional Evaluation 80 9.3 Short-Circuit Evaluation 83 9.4 Repeated Evaluation: Loops 85 9.5 Exception Handling 88 Built-in Exceptions 88 The throw function 89 Errors 90 The try/catch Scope of Variables 93 Scope constructs 93 10.1 Global Scope 94 10.2 Local Scope 94 Let Blocks 101 Loops and Comprehensions 102 10.3 Constants 103 11 Types 105 11.1 Type Declarations 106 11.2 Abstract Types managing worker processes 274 25.3 Data Movement 275 25.4 Global variables 276 25.5 Parallel Map and Loops 277 25.6 Remote References and AbstractChannels 279 25.7 Channels and RemoteChannels 279 Remote References

.... 27 9. Conditional statements and loops ..... 29 9.1. IF statements ..... 29 9.2. CASE expression ..... 30 9.3. WHILE loops ..... 31 9.4. FOR loops ..... 31 10. Keys and unique indices . NULL suppresses the sixth row (the one with Dept = 120). ### Chapter 9. Conditional statements and loops #### 9.1. IF statements If the test expression of an IF statement resolves to NULL, the THEN clause DISTINCT FROM" in your conditions—this operator too will never return NULL. #### 9.3. WHILE loops When evaluating the condition of a WHILE loop, NULL has the same effect as in an IF statement: if