break: Break out of a loop

Package: language

Usage

break

Description

The break statement is used to exit (break out of) the for or while loop in which it is found. In the case of nested loop constructs only the innermost loop is terminated. Unlike C usage the break statement does not break out of a switch.

Examples

1. Scan a list (file), printing each list element until either the list is exhausted or a list element "exit" or "quit" is encountered.

while (fscan (list, s1) != EOF) {
    if (s1 == "exit" || s1 == "quit")
        break
    print (s1)
}

2. Sum the pixels in a two dimensional array, terminating the sum for each line if a negative pixel is encountered, and terminating the entire process when the total sum passes a predefined limit.

total = 0
for (i=1;  i <= NCOLS;  i+=1) {
    for (j=1;  j <= NLINES;  j+=1) {
        if (pixel[i,j] < 0)
            break               # exit the J loop
        total += pixel[i,j]
    }
    if (total > NPHOT)
        break                   # exit the I loop
}

Bugs

See also

next, while, for