Documentation Index
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string
Strings in Soul represent sequences of characters enclosed in quotes. They support various operations for text manipulation, searching, and formatting.
Basic String Literals
Create strings using single or double quotes:
// Double quotes
message = "Hello, World!"
name = "Alice"
// Single quotes
greeting = 'Hello there!'
title = 'Soul Programming Language'
// Empty string
empty = ""
String Concatenation
Combine strings using the + operator:
firstName = "John"
lastName = "Doe"
fullName = firstName + " " + lastName // "John Doe"
// Multiple concatenation
greeting = "Hello, " + firstName + " " + lastName + "!"
String with Variables
Include variables in strings:
name = "Alice"
age = 30
message = "My name is " + name + " and I am " + age + " years old."
// With expressions
price = 19.99
total = "The total is $" + (price * 1.1)
String Escaping
Use escape characters for special characters:
// Escape quotes
message = "She said \"Hello\" to me"
quote = 'It\'s a beautiful day'
// Other escape sequences
newline = "Line 1\nLine 2"
tab = "Column 1\tColumn 2"
backslash = "Path: C:\\Users\\Alice"
String Methods
Common string operations:
text = "Hello, World!"
// Length
length = text.length() // 13
// Case conversion
upper = text.toUpperCase() // "HELLO, WORLD!"
lower = text.toLowerCase() // "hello, world!"
// Trimming
spaced = " Hello "
trimmed = spaced.trim() // "Hello"
String Searching
Find substrings and characters:
text = "Hello, World!"
// Check if string contains substring
hasHello = text.contains("Hello") // true
hasGoodbye = text.contains("Goodbye") // false
// Find index of substring
index = text.indexOf("World") // 7
notFound = text.indexOf("xyz") // -1
// Check start and end
startsWithHello = text.startsWith("Hello") // true
endsWithExclamation = text.endsWith("!") // true
String Replacement
Replace parts of strings:
text = "Hello, World!"
// Replace first occurrence
newText = text.replace("World", "Soul") // "Hello, Soul!"
// Replace all occurrences
repeated = "Hello Hello Hello"
replaced = repeated.replaceAll("Hello", "Hi") // "Hi Hi Hi"
String Splitting
Split strings into arrays:
text = "apple,banana,cherry"
fruits = text.split(",") // ["apple", "banana", "cherry"]
sentence = "Hello world from Soul"
words = sentence.split(" ") // ["Hello", "world", "from", "Soul"]
// Split with limit
limited = text.split(",", 2) // ["apple", "banana"]
String Slicing
Extract portions of strings:
text = "Hello, World!"
// Get substring
hello = text.substring(0, 5) // "Hello"
world = text.substring(7, 12) // "World"
// Get character at index
firstChar = text[0] // "H"
lastChar = text[text.length() - 1] // "!"
String Comparison
Compare strings:
str1 = "Hello"
str2 = "hello"
str3 = "Hello"
// Exact comparison
isEqual = (str1 == str3) // true
isDifferent = (str1 != str2) // true
// Case-insensitive comparison
isSameIgnoreCase = (str1.toLowerCase() == str2.toLowerCase()) // true
soul formatString(template, values) {
result = template
for (key, value in values) {
placeholder = "{" + key + "}"
result = result.replace(placeholder, value)
}
return result
}
// Usage
template = "Hello {name}, you are {age} years old"
formatted = formatString(template, {
"name": "Alice",
"age": 30
})
// "Hello Alice, you are 30 years old"
String Validation
Validate string content:
soul isValidEmail(email) {
if (email == null || email == "") {
return false
}
return email.contains("@") && email.contains(".")
}
soul isValidPassword(password) {
if (password == null || password.length() < 8) {
return false
}
hasLetter = false
hasDigit = false
for (i = 0; i < password.length(); i++) {
char = password[i]
if (char >= "a" && char <= "z" || char >= "A" && char <= "Z") {
hasLetter = true
}
if (char >= "0" && char <= "9") {
hasDigit = true
}
}
return hasLetter && hasDigit
}
String Manipulation
Advanced string operations:
// Reverse string
soul reverseString(str) {
if (str == null || str == "") {
return str
}
result = ""
for (i = str.length() - 1; i >= 0; i--) {
result += str[i]
}
return result
}
// Capitalize first letter
soul capitalize(str) {
if (str == null || str == "") {
return str
}
return str[0].toUpperCase() + str.substring(1).toLowerCase()
}
// Remove all whitespace
soul removeWhitespace(str) {
if (str == null) {
return null
}
return str.replace(" ", "").replace("\t", "").replace("\n", "")
}
String Joining
Join arrays into strings:
words = ["Hello", "World", "from", "Soul"]
sentence = words.join(" ") // "Hello World from Soul"
numbers = [1, 2, 3, 4, 5]
numberString = numbers.join(", ") // "1, 2, 3, 4, 5"
// Custom join function
soul joinWithAnd(items) {
if (items.length() == 0) {
return ""
}
if (items.length() == 1) {
return items[0]
}
if (items.length() == 2) {
return items[0] + " and " + items[1]
}
result = ""
for (i = 0; i < items.length() - 1; i++) {
result += items[i] + ", "
}
result += "and " + items[items.length() - 1]
return result
}
String Patterns
Common string patterns:
// Check if string is numeric
soul isNumeric(str) {
if (str == null || str == "") {
return false
}
for (i = 0; i < str.length(); i++) {
char = str[i]
if (char < "0" || char > "9") {
return false
}
}
return true
}
// Extract numbers from string
soul extractNumbers(str) {
if (str == null) {
return []
}
numbers = []
current = ""
for (i = 0; i < str.length(); i++) {
char = str[i]
if (char >= "0" && char <= "9") {
current += char
} else {
if (current != "") {
numbers.push(Number(current))
current = ""
}
}
}
if (current != "") {
numbers.push(Number(current))
}
return numbers
}
String Interpolation
Simple string interpolation:
soul interpolate(template, data) {
result = template
for (key, value in data) {
pattern = "${" + key + "}"
while (result.contains(pattern)) {
result = result.replace(pattern, value.toString())
}
}
return result
}
// Usage
template = "Hello ${name}, welcome to ${place}!"
message = interpolate(template, {
"name": "Alice",
"place": "Soul Programming"
})
// "Hello Alice, welcome to Soul Programming!"
String Encoding
Handle string encoding:
soul encodeForUrl(str) {
if (str == null) {
return null
}
// Simple URL encoding
return str.replace(" ", "%20")
.replace("&", "%26")
.replace("=", "%3D")
}
soul decodeFromUrl(str) {
if (str == null) {
return null
}
return str.replace("%20", " ")
.replace("%26", "&")
.replace("%3D", "=")
}
String Utilities
Utility functions for strings:
soul padLeft(str, width, char) {
if (char == null) {
char = " "
}
while (str.length() < width) {
str = char + str
}
return str
}
soul padRight(str, width, char) {
if (char == null) {
char = " "
}
while (str.length() < width) {
str = str + char
}
return str
}
soul truncate(str, maxLength, suffix) {
if (suffix == null) {
suffix = "..."
}
if (str.length() <= maxLength) {
return str
}
return str.substring(0, maxLength - suffix.length()) + suffix
}
Best Practices
- Use appropriate quotes: Choose single or double quotes consistently
- Escape special characters: Handle quotes and backslashes properly
- Validate input: Check for null and empty strings
- Use string methods: Leverage built-in string operations
- Handle Unicode: Be aware of character encoding issues
// Good - safe string operations
soul safeStringOperation(str) {
if (str == null) {
return ""
}
return str.trim().toLowerCase()
}
// Better - comprehensive string handling
soul processUserInput(input) {
if (input == null) {
return {
success: false,
error: "Input is null"
}
}
if (typeof input != "string") {
return {
success: false,
error: "Input must be a string"
}
}
// Clean and validate input
cleaned = input.trim()
if (cleaned == "") {
return {
success: false,
error: "Input cannot be empty"
}
}
if (cleaned.length() > 1000) {
return {
success: false,
error: "Input too long"
}
}
return {
success: true,
result: cleaned
}
}
