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Difference between revisions of "EDT:Writing statements"
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== For == | == For == | ||
| − | <br> | + | |
| + | After the following code runs, the value of sum is 30: | ||
| + | |||
| + | <source lang = "java"> | ||
| + | inputList int[] = [2,4,6,8,10]; | ||
| + | sum int = 0; | ||
| + | numberInList int = inputList.getSize(); | ||
| + | |||
| + | for (i int from 1 to numberInList by 1) | ||
| + | sum = inputList[i] + sum; | ||
| + | end | ||
| + | </short> | ||
| + | <br> | ||
== If == | == If == | ||
Revision as of 15:50, 13 February 2012
EGL provides general statements such as if and while, as well as action statements for accessing data sources or invoking external logic.
Contents
General statements
The general statements are case, continue, exit, for, if, move, return, throw, try, use, and while.
Case
The case statement responds to conditions at run time by executing one set of statements rather than another:
- You can test a criterion value. The following example invokes
mySecondFunction:
function test() x Int = 3; case (x) when (1) myFirstFunction(); when (2, 3, 4) mySecondFunction(); otherwise myDefaultFunction(); end end
- You can test a set of logical expressions. The following example displays only "x passes":
function test() x Int = 3; y Int = 5; z Int = 7; case when (x == 3) SysLib.writeStdOut("x passes"); when (y == 5) SysLib.writeStdOut("y passes"); when (z == 7) SysLib.writeStdOut("z passes"); otherwise SysLib.writeStdErr("You will not see this message."); end end end
As shown, no more than one clause ever executes. Control does not “fall through” from one clause to the next.
Continue
The EGL continue statement returns control to the start of a block of code controlled by a for, forEach, or while statement. The statement lets you return to a labeled statement of one of those kinds, or to the nearest embedding statement of one of those kinds.
The following example assumes that you have coded a print function named printReport.
for (i from 1 to 100 by 1) printReport(myList[i]); if ((i % 10) != 0) continue; end // if printReport(blankLine); end // for
That code prints the members of a list, inserting a blank line between each group of ten.
Exit
The EGL exit statement exits from a function, program, service, or run unit; or from a block of code controlled by a case, for, forEach, if, or while statement.
For
After the following code runs, the value of sum is 30:
inputList int[] = [2,4,6,8,10]; sum int = 0; numberInList int = inputList.getSize(); for (i int from 1 to numberInList by 1) sum = inputList[i] + sum; end </short> <br> == If == The following program shows '''If''' statements embedded in other '''If''' statements. <source lang="java"> program MyTestProgram // A binary search finds a value in a sorted (preferably short) list. function binarySearch(list int[], lowIndex int, highIndex int, value int) returns(int) while(true) middleIndex int = (lowIndex + highIndex) / 2; if(list[middleIndex] == value) return(middleIndex); else if(list[middleIndex] >= value) highIndex = middleIndex - 1; else if(list[middleIndex] < value) lowIndex = middleIndex + 1; end end end if(highIndex < lowIndex) return(-1); end end end function main() myNumbers int[] =[-6, -1, 2, 4, 7, 9 ]; valueOfInterest int = -1; lowestIndex int = 1; highestIndex int = myNumbers.getSize(); location int = binarySearch(myNumbers, lowestIndex, highestIndex, valueOfInterest); if (location == -1) SysLib.writeStdOut("Did not find " + valueOfInterest + "."); else SysLib.writeStdOut("The value of interest is " + valueOfInterest + ", at location " + location + "."); end end end
Move
Return
Throw
Try
Use
While
Action statements
The action statements are add, call, close, delete, execute, forEach, get, open, prepare, and transfer.