feat: add string_methods&properties.js

Author: ExploitEngineer

part1 (Basics)/10_compound_operators.js

@@ -1,41 +1,105 @@
-// INFO: String Methods & Properties
-// Before starting string methods and properties we need to know that strings are indexed. So basically we can access only single character of a string by doing something like this.
+// strings_methods&properties.js
 
-// Expression: "Hello World"[1]
-// Result: "e"
+// INFO: String Methods & Properties in JavaScript
 
-let message = "Hello World";
-let message1 = "Hello";
-let number = '1234';
-console.log(message[4]);
+/*
+Strings in JavaScript are sequences of characters and are indexed starting from 0.
+This means you can access individual characters using bracket notation.
+
+Example:
+"Hello World"[1]  // returns "e"
+*/
 
+// Accessing characters by index
+let message = "Hello World";
+console.log(message[4]); // Output: o
 
 // Properties
-// NOTE: There is only one property for string (which is length)
-console.log(message.length);
+// NOTE: The main property of strings is 'length' which returns the number of characters in the string.
+console.log(message.length); // Output: 11
+
+// Methods without arguments
+
+// Convert to uppercase
+console.log(message.toUpperCase()); // Output: "HELLO WORLD"
 
-// Methods without argument
-console.log(message.toUpperCase());
-console.log(message.toLowerCase());
+// Convert to lowercase
+console.log(message.toLowerCase()); // Output: "hello world"
 
+// Remove whitespace from both ends
 let newMessage = "    hi this is me .         ";
-console.log(newMessage.trim());
-console.log(newMessage.trimStart());
-console.log(newMessage.trimEnd());
-
-// Methods with argument
-console.log(message.includes("Hello"));
-console.log(message.indexOf("e"));
-console.log(message.replace('Hello', 'Hi'));
-console.log(message1.replaceAll('l', 'L'));
-console.log(message.concat(' ' + message1));
-console.log(number.padStart(11, '*'));
-console.log(number.padEnd(12, "-"));
-console.log(message.charAt(1));
-console.log(message.charCodeAt(0));
-console.log(message.split(' '));
+console.log(newMessage.trim()); // Output: "hi this is me ."
+console.log(newMessage.trimStart()); // Removes only the starting spaces
+console.log(newMessage.trimEnd()); // Removes only the ending spaces
+
+// Methods with arguments
+
+// Check if string includes substring
+console.log(message.includes("Hello")); // Output: true
+
+// Get index of first occurrence of character/string
+console.log(message.indexOf("e")); // Output: 1
+
+// Replace first occurrence of substring
+console.log(message.replace("Hello", "Hi")); // Output: "Hi World"
+
+// Replace all occurrences (ES2021 feature)
+console.log("Hello Hello".replaceAll("l", "L")); // Output: "HeLLo HeLLo"
 
+// Concatenate strings
+console.log(message.concat(" " + "Everyone")); // Output: "Hello World Everyone"
+
+// Pad string from start to reach a certain length
+let number = "1234";
+console.log(number.padStart(11, "*")); // Output: *******1234
+
+// Pad string from end to reach a certain length
+console.log(number.padEnd(12, "-")); // Output: 1234--------
+
+// Get character at specific index
+console.log(message.charAt(1)); // Output: "e"
+
+// Get Unicode value of character at specific index
+console.log(message.charCodeAt(0)); // Output: 72 (Unicode for 'H')
+
+// Split string into array based on separator
+console.log(message.split(" ")); // Output: [ 'Hello', 'World' ]
 
 // String Template Literals
-const templateString = 17;
-console.log(`I am ${templateString} years old`);
+const age = 17;
+console.log(`I am ${age} years old`); // Output: "I am 17 years old"
+
+// Multi-line strings using template literals
+const multiLine = `
+This is line 1
+This is line 2
+This is line 3
+`;
+console.log(multiLine);
+
+/*
+Summary:
+
+Property:
+- length
+
+Methods (no argument):
+- toUpperCase()
+- toLowerCase()
+- trim()
+- trimStart()
+- trimEnd()
+
+Methods (with argument):
+- includes(substring)
+- indexOf(substring)
+- replace(searchValue, newValue)
+- replaceAll(searchValue, newValue)
+- concat(string)
+- padStart(targetLength, padString)
+- padEnd(targetLength, padString)
+- charAt(index)
+- charCodeAt(index)
+- split(separator)
+- Template Literals with backticks for interpolation and multi-line strings
+*/