Gallery

csHjavaA-2019

about this document

revision

Explore

read text files

file names

assignment: read text file, use substring

this is a assignment program

read a list of values from a text file

use length function to calculate the size of a file name

use substring to select some letters from a text value

program requirement

read the file values into an array

display all the array values in full as well as the length of each string

display the end section of all array values

display the start of some array values which match a target value

substring: start/end, using if()

sometime substring is used to select characters at the end of the string

the position at the end of a string depends on how long the string is, so the length function helps

select characters at start / end of a string: use the length of the string to help select the last character

start always begins at position 0, the length of the first string is 9, the second 12 and the third 11

end is always at the position given by the length of the string, use this for the second parameter

count back from the end for a substring at the end of a string to calculate the first parameter, using (-2) gives the last two characters

substring can be used with an if condition and the .equals function

Use substring with an if() conditional construct to decide option based on substring value

constructs used

file handling

open file

read file

close file

data structure

• string array

control structure

fixed loop using index

if conditional

substring function

startswith function

Input requirements

Sample data from file, file names including the file type extension

Output requirements

Display full file list with name and extension

file extensions only for all files

png files, display without extension

design: main steps

code: repl program

⁠

Loading…⁠

⁠

substring: start/end, using if()

Want to print your doc?
This is not the way.

Try clicking the ⋯ next to your doc name or using a keyboard shortcut (

CtrlP

) instead.