Question 1

What is a diff checker?

Accepted Answer

Diff checker compares two texts line-by-line to highlight differences: additions (new content), deletions (removed content), and modifications (changed content). Color coding shows changes: green for added, red for removed, yellow for modified. Used for code review, document comparison, and change tracking.

Question 2

How do I compare two code files?

Accepted Answer

Paste original code in left textarea, modified code in right. Diff checker highlights differences. Use git diff for version control: 'git diff file1 file2' or 'git diff HEAD~1 HEAD'. Online diff tools work for quick comparisons without git. IDEs like VS Code have built-in diff view.

Question 3

What is unified diff format?

Accepted Answer

Unified diff format: header with file names and timestamps, then chunks starting with @@ line numbers @@. Lines prefixed with - (removed), + (added), or space (unchanged). Example: -old line, +new line. Git uses unified diff by default. Patch files use this format.

Question 4

Why use diff for code review?

Accepted Answer

Diff view focuses attention on changes rather than entire file. Reviewers see exactly what changed: new features, bug fixes, refactoring. Faster review than reading whole file. Git pull requests show diffs. Side-by-side diff makes spotting errors easier. Essential for catching bugs before merge.

Question 5

How do I create a git diff?

Accepted Answer

Git diff commands: 'git diff' shows unstaged changes, 'git diff --staged' shows staged changes, 'git diff HEAD' shows all uncommitted changes, 'git diff commit1 commit2' compares commits, 'git diff branch1 branch2' compares branches. Output in unified format. Use 'git diff --color-words' for word-level changes.

Text Diff Checker

Use Cases