![]() if "conditional expression 1" is true, perform the statements associated with that condition, then exit to the statement following the End If if "conditional expression 1" is false, then check "conditional expression 2" - if "conditional expression 2" is true, perform the statements associated with that condition, then exit to the statement following the End If, and so on. Note also the keyword ElseIf is one word. Else If Then Else Note that one or more Else If clauses are "sandwiched" between the first "If" clause and the last "Else" clause. Extended (Nested) Block If Statement Format/Syntax: If Then Else If Then. In Pascal, the Multiple selections can be implemented in one of two ways: with an extended (Nested) block If structure, or with the Case statement structure. When the situation arises where you need to choose between more than two alternatives, an extended form of the selection structure, called the case structure, must be used. The multiple-selection structure (Case Statement or Nested If Statement) In any case, program control will resume with the statement following after the If statement. If the conditional expression is false, the statements after the keywords Else will be executed (and the statements between the keywords Then and Else will be bypassed). Syntax If Then Else If the conditional expression is true, the statements between the keywords Then and Else will be executed (and the statements after the keywords Else will be bypassed). The IF…THEN…ELSE selection control structure allows one set of statements to be executed if a condition is true and another set of actions to be executed if a condition is false.Īfter either the true set of actions or the false set of actions is taken, program control resumes with the next statement (the statement that would be placed below the connector in the flowchart above). The If-Then-Else statement is a "two-alternative" decision (Actions are taken on both the "If" side and the "Else" side). This is used where there are two options to choose. The double-selection structure (If.Then…Else) After the true set of actions is executed, program control resumes with the next statement. The IF…THEN selection control structure allows a set of statements to be executed if a condition is true only. This is used where there is only one option to choose. The selection structure specifies alternate courses of program flow.Ī) The single-selection structure (IF…THEN Statement) Intelligently so that it can provide useful output or feedback to the user. Important part of programming because it can help to solve practical problems User, and control the program flow in the process. ![]() Selection allows the program to make decisions when it processes input from the Is executed once, and they are executed in the same order that they are listed. ![]() Statements executed one after another in order. "A"<"B"<"C"<"D".<"Z" and number are less than letters. However, there areĬertain rules to follows: Upper case letters are less than lowercase letters, You can also compare strings with the above operators. In addition to conditional operators, there are a few logical operators which offerĪdded power to the Pascal programs. Take, whether to execute a program or terminate the program and more. Tools, they let the program compare data values and then decide what action to To control the program flow, we can use various conditional operators. There are Three Control Structures namely:Ĭonditional/Relational/Comparison Operators Control structures determine how a set of For that purpose, Pascal providesĬontrol structures that serve to specify what has to be done by our program, Process it may repeat code or take decisions. These operators are shown in Table below Operator Meaning = Equal to > More than = More than and equal Not Equal toĪ program is usually not limited to a linear sequence of instructions. Conditional operators are very powerful tools, they let the program compare data values and then decide what action to take, whether to execute a program or terminate the program and more. Basically, they resemble mathematical operators. ![]() Looping/Iteration/Repetition Conditional/Relational/Comparison Operators To control the program flow, we can use various conditional operators.There are Three Control Structures namely: Control structures determine how a set of instructions are executed. For that purpose, Pascal provides control structures that serve to specify what has to be done by our program, when and under which circumstances. During its process it may repeat code or take decisions. Control Structures-Selection 1 Program Control Structures - PASCAL A program is usually not limited to a linear sequence of instructions.
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