The for loop, or the for statement, is used whenever it is essential to repeat statement(s) in the script or function, and whenever it is known ahead of time how many times the statements will be repeated. The statements which are repeated are termed as the action of the loop. For illustration, it might be known that the action of the loop will be repeated five times. The terms used are that we iterate through the action of the loop five times.
The variable which is used to iterate through values is termed as the loop variable, or an iterator variable. For illustration, the variable may iterate through the integers 1 through 5 (example, 1, 2, 3, 4, and then 5). Though variable names in common must be mnemonic, it is general for an iterator variable to be given the name i (and if more than one iterator variable is required, i, j, k, l, etc.) This is historical, and is since of the way integer variables were named in the FORTRAN.
Though, in MATLAB both i & j are built-in values for 1 - , therefore using either as a loop variable will override that value. If this is not an issue, then it is acceptable to use i as a loop variable.
The common form of the for loop is as shown below:
for loopvar = range
where loopvar is the loop variable, range is the range of values by which the loop variable is to iterate, and the action of loop contains all the statements up to the end. The range can be identified by using any vector, but usually the simplest way to identify the range of the values is to use the colon operator.