Is string a keyword?
A string is NOT a keyword. It is one of the names of data types declared in the standard library.
How to check if a string is a keyword in C++?
- In C++ there is no special method to check whether the given string is a keyword or not. But there are a set of keywords present which is listed below-
"auto", "break", "case", "char", "const", "continue", "default", "do", "double", "else", "enum", "extern", "float", "for", "goto", "if", "int", "long", "register", "return", "short", "signed", "sizeof", "static", "struct", "switch", "typedef", "union", "unsigned", "void", "volatile", "while"
- So, we need to check whether our search word is present in the list or not to determine whether it is a keyword or not. As there is no keyword "string" in the above-mentioned list, a string is not a keyword.
How to check if a string is a keyword in Java?
- Java provides a method iskeyword() which is used to find whether the given string is a keyword or not. It is present in javax.lang.model.SourceVersion package. It will return a boolean value either True or False.
Syntax:
SourceVersion.isKeyword("word_to_check")
Parameters:
This method accepts a string to check whether it is a keyword or not.
Returns:
Boolean values - True or False.
How to check if a string is a keyword in Python?
- Python provides a method iskeyword() which is used to find out whether the given string is a keyword or not. It is present in the keyword built-in module. So, before using this method we need to import the keyword module.
- The iskeyword() method accepts a word/string as a parameter and returns a Boolean value True or False based on the input argument. It returns true for all the reserved words and for the rest it will give the result as False.
Syntax:
keyword.iskeyword("word_to_check")
Below is the code for implementing the methods to check if "string" is a keyword or not.
// C++ program for the above approach
#include <bits/stdc++.h>
using namespace std;
set<string> keywords = { "alignas",
"alignof",
"and",
"and",
"and_eq",
"asm",
"atomic_cancel",
"atomic_commit",
"atomic_noexcept",
"auto",
"bitand",
"bitor",
"bool",
"break",
"case",
"catch",
"char",
"char16_t",
"char32_t",
"class",
"compl",
"concept",
"const",
"constexpr",
"const_cast",
"continue",
"co_await",
"co_return",
"co_yield",
"decltype",
"default",
"delete",
"do",
"double",
"dynamic_cast",
"else",
"enum",
"explicit",
"export",
"extern",
"false",
"float",
"for",
"friend",
"goto",
"if",
"import",
"inline",
"int",
"long",
"module",
"mutable",
"namespace",
"new",
"noexcept",
"not",
"not_eq",
"nullptr",
"operator",
"or",
"or_eq",
"private",
"protected",
"public",
"register",
"reinterpret_cast",
"requires",
"return",
"short",
"signed",
"sizeof",
"static",
"static_assert",
"static_cast",
"struct",
"switch",
"synchronized",
"template",
"this",
"thread_local",
"throw",
"true",
"try",
"typedef",
"typeid",
"typename",
"union",
"unsigned",
"using",
"virtual",
"void",
"volatile",
"wchar_t",
"while",
"xor",
"xor_eq" };
// Function to check c++ keyword
bool is_keyword(string s) { return keywords.count(s); }
int main()
{
// Passing String to iskeyword() to check
// if it is a keyword or not
cout << is_keyword("string");
return 0;
}
// This code is contributed by rakeshsahni
// Import necessary packages
import java.io.*;
import javax.lang.model.SourceVersion;
class GFG {
public static void main(String[] args)
{
// Checking whether string is a keyword or not
System.out.println(
SourceVersion.isKeyword("string"));
}
}
# Import necessary packages
import keyword
if __name__ == '__main__':
# Passing String to iskeyword() to check
# if it is a keyword or not
print(keyword.iskeyword('String'))
using System;
using System.Collections.Generic;
class Program
{
// HashSet to store C++ keywords
static HashSet<string> keywords = new HashSet<string>
{
"alignas", "alignof", "and", "and_eq", "asm", "atomic_cancel", "atomic_commit", "atomic_noexcept", "auto",
"bitand", "bitor", "bool", "break", "case", "catch", "char", "char16_t", "char32_t", "class", "compl",
"concept", "const", "constexpr", "const_cast", "continue", "co_await", "co_return", "co_yield", "decltype",
"default", "delete", "do", "double", "dynamic_cast", "else", "enum", "explicit", "export", "extern", "false",
"float", "for", "friend", "goto", "if", "import", "inline", "int", "long", "module", "mutable", "namespace",
"new", "noexcept", "not", "not_eq", "nullptr", "operator", "or", "or_eq", "private", "protected", "public",
"register", "reinterpret_cast", "requires", "return", "short", "signed", "sizeof", "static", "static_assert",
"static_cast", "struct", "switch", "synchronized", "template", "this", "thread_local", "throw", "true", "try",
"typedef", "typeid", "typename", "union", "unsigned", "using", "virtual", "void", "volatile", "wchar_t", "while",
"xor", "xor_eq"
};
// Function to check if a word is a C++ keyword
static bool IsKeyword(string s) => keywords.Contains(s);
static void Main()
{
// Passing a string to IsKeyword() to check if it is a keyword or not
Console.WriteLine(IsKeyword("string"));
// Note: In C#, Console.WriteLine automatically adds a new line after the printed text.
}
}
// A function to check if a given word is a JavaScript keyword or not
const isKeyword = (word) => {
// An array containing all the JavaScript keywords
const keywords = [
"abstract", "await", "boolean", "break", "byte",
"case", "catch", "char", "class", "const", "continue",
"debugger", "default", "delete", "do", "double",
"else", "enum", "export", "extends", "false", "final",
"finally", "float", "for", "function", "goto", "if",
"implements", "import", "in", "instanceof", "int",
"interface", "let", "long", "native", "new", "null",
"package", "private", "protected", "public", "return",
"short", "static", "super", "switch", "synchronized",
"this", "throw", "throws", "transient", "true", "try",
"typeof", "var", "void", "volatile", "while", "with",
"yield"
];
// Check if the word is in the keywords array
return keywords.includes(word);
};
// Calling the function with a test word and storing the result
let ans = isKeyword('String');
// Printing the result
console.log(ans);
// Contributed by adityae15
Output
false
