C Sharp (C#) - File IO
You want to read a text file and count how many lines contain the word "error" (case insensitive). Which code snippet correctly does this?
You want to read a text file and count how many lines contain the word "error" (case insensitive). Which code snippet correctly does this?
hard🚀 Application Q15 of Q15
Step-by-Step Solution
Solution:
Step 1: Choose method to read lines
File.ReadAllLinesreturns an array of lines, perfect for line-by-line processing.Step 2: Count lines with "error" case-insensitive
var lines = File.ReadAllLines("log.txt"); int count = lines.Count(line => line.ToLower().Contains("error")); converts each line to lowercase and checks if it contains "error", then counts matches using LINQ.Step 3: Check other options
string content = File.ReadAllText("log.txt"); int count = content.Split('\n').Count(line => line.Contains("error")); uses ReadAllText but misses case-insensitive check. var lines = File.ReadAllLines("log.txt"); int count = 0; foreach(var line in lines) { if(line.Contains("error")) count++; } misses case-insensitive check. string[] lines = File.ReadAllText("log.txt").Split('\n'); int count = lines.Count(line => line.Contains("error")); incorrectly assigns ReadAllText to string array without ToLower.Final Answer:
var lines = File.ReadAllLines("log.txt"); int count = lines.Count(line => line.ToLower().Contains("error")); -> Option CQuick Check:
Use ReadAllLines + ToLower + Count for case-insensitive search [OK]
Quick Trick: Use ReadAllLines and ToLower for case-insensitive line checks [OK]
Common Mistakes:
MISTAKES- Ignoring case sensitivity
- Using ReadAllText but treating as array
- Not converting lines to lowercase
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