[SalesForce] Omission or inclusion of curly braces in for loop logic – what is the difference

I see differences in use of curly braces in for loops quite frequently.

One style is to be very explicit with the curly braces at the end of a for/if statement. For example:

for (Opportunity opp : opportunityList){

Another style I see is that there is an omission of this curly brace at the end of a for/if statement. For example:

for (Opportunity opp : opportunityList)

So as I understand it, the difference is that the former is explicit and the latter is implicit and usage is based on personal preferance (the latter being more concise, but the former maybe being force of habit).

Is that correct? Or is there a difference between the two in terms of performance?

Thanks,

Best Answer

If the number of statements following the for/if is single you don't have to use curly braces.

But if the number of statements is more than one, then you need to use curly braces. If you don't use curly brace in this scenario, then the first line will execute only in the context of for/if, other lines will execute at all times.

Example:

if(condition){ // Not required
    statement1;
} // Not required

if(condition) { // Required
    statement1;
    statement2;
} // Required

if(condition)
statement1; // This will execute if condition satisfies
statement2; // This will execute anyway

for(iteration condition){ // Not required
    statement1;
} // Not required

for(iteration condition) { // Required
    statement1;
    statement2;
} // Required

for(iteration condition)
statement1; // This will execute for n times
statement2; // This will execute only once

Hope it helps to understand.

Related Solutions

[SalesForce] the difference between curly brackets and parentheses when setting a new map

With no parameters, new Map<KeyType, DataType>() and new Map<KeyType, DataType> { } have identical behavior. I tested a loop of 50,000 new maps of each and grabbed the timestamps from the logs, and they were almost consistently 64ms for 50,000 maps (we can't account for server load, however, so this performance may vary); approximately 0.001ms to create a new map either way.

The difference, however, is that each form has a different purpose. The parenthetical version is used to create a map from a list of SObject records or another map. They look like this:

Map<String, String> a = new Map<String, String>();
Map<String, String> b = new Map<String, String>(a);
Map<Id, SObject> c = new Map<Id, SObject>([SELECT Id,Name FROM Contact]);

The bracketed version is used to instantiate a map with values:

Map<String, String> a = new Map<String, String>{
  'a' => '1',
  'b' => '2',
  'c' => '3' };

[SalesForce] the difference between System.currentPageReference() and ApexPages.currentPage()

The two are synonymous. The former is the classic means of accessing the current page, while the new method was introduced as a part of the recent normalization of functions. Other functions have also been duplicated in more appropriate spaces, such as System.Now() vs DateTime.Now() and System.today() versus Date.Today(). It is safe to use either in current code, although one would expect the classic version to be deprecated eventually. Note also that ApexPages.CurrentPage() no longer appears in the documentation, as far as I can tell.

Proof:

Controller

public with sharing class versus {
    public boolean getIsEqual() { return apexpages.currentpage() === system.currentpagereference(); }
}

Page

<apex:page controller="versus">
    {!isEqual}
</apex:page>

Output

true

Conclusion

Since === compares two memory locations, and this operator returning true means that both functions are literally returning the same value.