Sas if statement

The ELSE statement is optional. It can be used to execute a statement if the condition is not true. Sometimes, sas if statement, we might need to execute more than one statement when the condition is met. Sign In.

Continues processing only those observations that meet the condition of the specified expression. The subsetting IF statement causes the DATA step to continue processing only those raw data records or those observations from a SAS data set that meet the condition of the expression that is specified in the IF statement. If the expression is true for the observation its value is neither 0 nor missing , SAS continues to execute the DATA step and includes the observation in the output data set. If the expression is false its value is 0 or missing , no further statements are processed for that observation or record, the current observation is not written to the data set, and the remaining program statements in the DATA step are not executed. SAS immediately returns to the beginning of the DATA step because the subsetting IF statement does not require additional statements to stop processing observations. This matches patterns that occur at the beginning of a string. Here is an example.

Sas if statement

An if-then statement can be used to create a new variable for a selected subset of the observations. For each observation in the data set, SAS evaluates the expression following the if. When the expression is true, the statement following then is executed. When the expression is false, SAS ignores the statement following then. For a person whose age is less than 65, the variable older will be missing. An optional else statement can be included if-then-else to provide an alternative action when the if expression is false. An optional else-if statement can follow the if-then statement. SAS evaluates the expression in the else-if statement only when the previous expression is false. Note that this if-then-else-if statement could equivalently be written. An if statement can be followed by exactly one else statement or by many else-if statements.

I try to get the clue but still I am not clear. The DO group starts with the DO statement.

Again, once you've read your data into a SAS data set, you probably want to do something with it. A common thing to do is to change the original data in some way in an attempt to answer a research question of interest to you. In the last lesson, we learned how to use assignment statements and functions to add some information to all of the observations in the data set. In this lesson, we will learn how to use if-then-else statements to add some information to some but not all of the observations in your data set. In this lesson, we investigate a number of examples that illustrate how to change a subset of the observations in our data set. In SAS, the most common way to select observations that meet a certain condition is to utilize an if-then statement. The basic form of the statement is:.

To perform an operation conditionally, use an IF statement to test an expression. The IF expression is evaluated first. If the expression is true, execution flows through the THEN alternative. If the expression is false, the ELSE statement, if present, is executed. Otherwise, the next statement is executed. If the largest value found in matrix is less than 20, P is set to 0. Otherwise, P is set to 1. Any number of nesting levels is allowed.

Sas if statement

The subsetting IF statement causes the DATA step to continue processing only those raw data records or those observations from a SAS data set that meet the condition of the expression that is specified in the IF statement. That is, if the expression is true for the observation or record its value is neither 0 nor missing , SAS continues to execute statements in the DATA step and includes the current observation in the data set. If the expression is false its value is 0 or missing , no further statements are processed for that observation or record, the current observation is not written to the data set, and the remaining program statements in the DATA step are not executed. SAS immediately returns to the beginning of the DATA step because the subsetting IF statement does not require additional statements to stop processing observations. When you create SAS data sets, use the subsetting IF statement when it is easier to specify a condition for including observations. The two statements work differently and produce different output data sets in some cases. The most important differences are summarized as follows:. The subsetting IF statement selects observations that have been read into the program data vector.

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Note : In the upper right-hand corner of the code block you will have the option of copying the code to your clipboard or downloading the file to your computer. Our comparisons could just as easily involve character variables. PUT: List. Hence, we have another good programming habit Create an Account Login. The basic form of the statement is:. Cookie Settings Accept. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. That's certainly one way of assigning grades, but it's probably not going to make John very happy. Our focus there was primarily on the assignment statement. Review the output from the PRINT procedure to convince yourself that the letter grades have been assigned correctly.

With SAS 9.

Oh, one more point. For example putting if only without else how it works? It's just a matter of preference. PUT: Column. First, note that we continue to work with the grades data set from the last lesson. The following SAS program creates a character variable status , whose value is "Failed" IF the student's first exam grade is less than 65, otherwise i. The following SAS program illustrates the use of alternative intervals as well as the alternative syntax for the comparison operators:. Thus, we should stick to another good programming habit: always program for missing values. All Rights Reserved. What happened?!