GOTO statement

Dijkstra, E., "GoTo Statement Considered Harmful," Communications Association Computing tfachinery, 11 (1968) 147-148. 

Since many digital waveforms are periodic, a GOTO statement is provided for looping. The attributes in Table 8-3 and shown in the screen capture produce a clock frequency of 1 kHz for four cycles and then 500 Hz for an infinite number of cycles ... 

Note that not all of the attributes are shown in the screen capture above. The line GOTO LOOPl 3 TIMES means execute the GOTO statement 3 times. The line GOTO L00P2 - 7 TIMES means execute the GOTO statement an infinite number of times. These attributes describe the waveform ... 

We deliberately avoided the use of some elegant constructions as WHILE. .. WEND structure, SWAP statement, ON ERROR condition and never broke up a single statement into several lines. Although this self-restraint implies that we had to give up some principles of structural programming (e.g., we used more GOTO statements than it was absolutely necessary), we think that the loss is compensated by the improved portability of the programs. 

VBA supports If...Then and If...Then...Else or Elself structures, very similar to the Excel worksheet function IF. In addition, VBA provides the Select Case decision structure, similar to the ON value GOTO statement in BASIC. 

If these checks turn up no problems, the program falls through to the action routine for the specific verb. The tool used is the GOTO statement found in line 1430 above. It sends the program to line 2000, shown below ... 

The goto statement is sometimes used to direct program control when a program exception or error occurs. Alternative constructs that can be used in structured programming include (a) the return statement, which returns control to the end of the current function (b) the break statement, which terminates the inner most loop and (c) the continue statement, which returns to the next iteration of the innermost loop. 

Programming techniques will be fully structured there will be no labelled statements and no goto statements. 

Line number Integer (whole number) that begins each line of a BASIC program and serves as a kind of serial number for that line. Line numbers also serve as targets for GOTO statements. 

One of the tenets of structured programming is that GOTO statements (as in line 125 above), used carelessly, are the cause of many programming errors. All modern versions of BASIC allow the user to rewrite the above program without using GOTO statements as ... 

The collection of lines starting with 10 0 DO and ending with 12 5 LOOP is known as a loop. The interior lines of the loop are carried out repeatedly, as in the example by using a GOTO statement. Notice, in addition, that the program is written in mixed case (using both upper- and lowercase letters), and the interior lines of the loop are indented. All modern versions of BASIC allow these stylistic improvements. 

Eliminating the GOTO statement (line 125) removes the need to reference line numbers in the program. The line numbers themselves, no longer serving a useful purpose, can now be eliminated to get ... 

As an illustration of the weaknesses of the original IF-THEN and GOTO statements, suppose we want to check a student s answer to a question in a drill program (the correct answer is 17) ... 

Choi, J.D., Ferrante, J. Static slicing in the presence of goto statements. ACM Trans. Program. Lang. Syst. 16(4), 1097-1113 (1994)... 

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