Statement Coverage Or Line Coverage

Statement coverage is also known as line coverage.
The formula to calculate statement coverage is:

Statement Coverage=SC
SC=(Number of statements exercised/Total number of statements)*100

Studies in the software industry have shown that black-box testing may actually achieve only 60% to 75% statement coverage, this leaves around 25% to 40% of the statements untested.

To illustrate the principles of code coverage let's take one pseudo-code which is not specific to any programming language. We have numbered the code lines just to illustrate the statement coverage example however this may not always be correct.

    READ X
    READ Y
    IF X>Y
    PRINT “X is greater than Y”
    ENDIF

Let us see how can we achieve 100% code coverage for this pseudo-code, we can have 100% coverage by just one test set in which variable X is always greater than variable Y.

    TEST SET 1: X=10, Y=5

A statement may be a single line or it may be spread over several lines. A statement can also contain more than one statement. Some code coverage tools group statements that are always executed together in a block and consider them as one statement.