diff --git a/src/classnames/index.test.ts b/src/classnames/index.test.ts
index f139ced..428344a 100644
--- a/src/classnames/index.test.ts
+++ b/src/classnames/index.test.ts
@@ -1,77 +1,6 @@
-import {classNames, isBooleanString, isString} from "./index";
+import {classNames} from "./index";
 
 describe("classnames", () => {
-  describe('isString function', () => {
-    it('should return true for string', () => {
-      expect(isString('test')).toBe(true);
-    });
-
-    it('should return false for non-string', () => {
-      expect(isString(123)).toBe(false);
-      expect(isString(null)).toBe(false);
-      expect(isString(undefined)).toBe(false);
-      expect(isString(true)).toBe(false);
-      expect(isString({})).toBe(false);
-      expect(isString([])).toBe(false);
-    });
-  });
-
-  describe('isBooleanString', () => {
-    it('should return false for true as boolean', () => {
-      expect(isBooleanString(true)).toBe(false);
-    });
-
-    it('should return false for false as boolean', () => {
-      expect(isBooleanString(false)).toBe(false);
-    });
-
-    it('should return false for null', () => {
-      expect(isBooleanString(null)).toBe(false);
-    });
-
-    it('should return false for undefined', () => {
-      expect(isBooleanString(undefined)).toBe(false);
-    });
-
-    it('should return false for number 1', () => {
-      expect(isBooleanString(1)).toBe(false);
-    });
-
-    it('should return false for number 0', () => {
-      expect(isBooleanString(0)).toBe(false);
-    });
-
-    it('should return true for "true" string', () => {
-      expect(isBooleanString("true")).toBe(true);
-    });
-
-    it('should return true for "1" string', () => {
-      expect(isBooleanString("1")).toBe(true);
-    });
-
-    it('should return false for "false" string', () => {
-      expect(isBooleanString("false")).toBe(false);
-    });
-
-    it('should return false for "0" string', () => {
-      expect(isBooleanString("0")).toBe(false);
-    });
-
-    it('should return false for arbitrary string', () => {
-      expect(isBooleanString("hello")).toBe(false);
-    });
-
-    // Test for objects and arrays (should return false)
-    it('should return false for empty object', () => {
-      expect(isBooleanString({})).toBe(false);
-    });
-
-    it('should return false for empty array', () => {
-      expect(isBooleanString([])).toBe(false);
-    });
-  });
-
-  describe('classNames function', () => {
     it('should return an empty string if no arguments are provided', () => {
       expect(classNames()).toBe('');
     });
@@ -85,27 +14,30 @@ describe("classnames", () => {
     });
 
     it('should filter out false keys in ClassMap and include true keys', () => {
-      expect(classNames({ class1: true, class2: false })).toBe('class1');
+      expect(classNames({class1: true, class2: false})).toBe('class1');
     });
 
     it('should filter out false keys in ClassMap and include true keys and add class3', () => {
-      expect(classNames({ class1: true, class2: false }, "class3")).toBe('class1 class3');
+      expect(classNames({class1: true, class2: false}, "class3")).toBe('class1 class3');
     });
 
     it('should filter out false keys in ClassMap and include true keys and add class3', () => {
-      expect(classNames({ class1: true, class2: false }, undefined, "class3")).toBe('class1 class3');
+      expect(classNames({class1: true, class2: false}, undefined, "class3")).toBe('class1 class3');
     });
 
     it('should handle a combination of all types of arguments', () => {
-      expect(classNames('class1', undefined, null, { class2: true, class3: false }, 'class4')).toBe('class1 class2 class4');
+      expect(classNames('class1', undefined, null, {
+        class2: true,
+        class3: false
+      }, 'class4')).toBe('class1 class2 class4');
     });
 
     it('should ignore object arguments with non-boolean values except strings like "true" or "false" or "1" or "2"', () => {
-      expect(classNames({ class1: "true", class2: 123, class3: "1" } as any)).toBe('class1 class3');
+      expect(classNames({class1: "true", class2: 123, class3: "1"} as any)).toBe('class1 class3');
     });
 
     it('should only include keys with boolean true values in mixed objects', () => {
-      expect(classNames({ class1: true, class2: "false", class3: 0 } as any)).toBe('class1');
+      expect(classNames({class1: true, class2: "false", class3: 0} as any)).toBe('class1');
     });
 
     it('should ignore empty strings', () => {
@@ -125,11 +57,11 @@ describe("classnames", () => {
     });
 
     it('should ignore nested objects', () => {
-      expect(classNames({ class1: true, nested: { class2: true }} as any)).toBe('class1');
+      expect(classNames({class1: true, nested: {class2: true}} as any)).toBe('class1');
     });
 
     it('should include class names with leading or trailing whitespaces as-is', () => {
-      expect(classNames(' class1 ', 'class2 ')).toBe(' class1  class2 ');
+      expect(classNames(' class1 ', 'class2 ')).toBe('class1 class2');
     });
 
     it('should include class names with array', () => {
@@ -145,10 +77,42 @@ describe("classnames", () => {
     });
 
     it('should filter out false keys in ClassMap and include true keys', () => {
-      expect(classNames({ class1: true, class2: false })).toBe('class1');
+      expect(classNames({class1: true, class2: false})).toBe('class1');
     });
 
+    it('evaluate all features', () => {
+      expect(classNames('a', ['b', 'c'], {d: true}, ['e', {f: true}, ' g', 'h ', ' i ', {' j': true}], ' k', 'l ', ' m ')).toBe('a b c d e f g h i j k l m');
+    });
 
-  });
+    it('should return empty string for no arguments', () => {
+      expect(classNames()).toBe('');
+    });
+
+    it('should concatenate class names', () => {
+      expect(classNames('a', 'b')).toBe('a b');
+    });
 
-})
+    it('should omit falsy values', () => {
+      expect(classNames('a', null, false, 'b')).toBe('a b');
+    });
+
+    it('should include truthy values from an object', () => {
+      expect(classNames('a', {'b': true, 'c': false}, 'd')).toBe('a b d');
+    });
+
+    it('should work with arrays', () => {
+      expect(classNames(['a', 'b'])).toBe('a b');
+    });
+
+    it('should work with nested arrays', () => {
+      expect(classNames(['a', ['b', 'c']])).toBe('a b c');
+    });
+
+    it('should work with arrays containing objects', () => {
+      expect(classNames(['a', {'b': true}])).toBe('a b');
+    });
+
+    it('should work with deeply nested structures', () => {
+      expect(classNames(['a', ['b', {'c': true}], [['d', {'e': true}]]])).toBe('a b c d e');
+    });
+  });
diff --git a/src/classnames/index.ts b/src/classnames/index.ts
index a536571..385a59e 100644
--- a/src/classnames/index.ts
+++ b/src/classnames/index.ts
@@ -1,49 +1,64 @@
-export type ClassValue = string | undefined | null | boolean;
-export type ClassMap = Record<string, boolean | string | number>;
+export type ClassValue = string | boolean | ClassValueArray | ClassMap;
+export type ClassValueArray = ClassValue[];
+export type ClassMap = { [key: string]: string | boolean };
 
-export function isString(value: unknown): value is string {
-  return typeof value === "string";
-}
+export function classNames(...args: ClassValue[]): string {
+  const classes: string[] = [];
 
-export function isBooleanString(value: unknown): boolean {
-  return ["true", "1"].includes(value as string);
-}
+  for (let i = 0; i < args.length; i++) {
+    processArg(args[i], classes);
+  }
 
-export function classNames(...args: (ClassValue | ClassMap | string | string[])[]): string {
-  function processArg (arg: ClassValue | ClassMap | string): string[] {
-    if (arg === undefined || arg === null || typeof arg === "boolean") {
-      return [];
-    }
+  let finalClasses = '';
+  let isFirstClass = true;
 
-    if (Array.isArray(arg)) {
-      return arg.filter(isString);
+  for (let i = 0; i < classes.length; i++) {
+    // Ignore boolean 'true'
+    if (classes[i] === 'true') {
+      continue;
     }
 
-    if (typeof arg === "object") {
-      return Object.keys(arg)
-        .map((key) => {
-          const value = arg[key];
-          if (value === true) {
-            return key;
-          }
-          if (isString(value) && isBooleanString(value)) {
-            return key;
-          }
-          return null;
-        })
-        .filter(Boolean)
-        .filter(isString);
+    // Trim each class
+    const trimmedClass = classes[i].trim();
+
+    if (trimmedClass) {
+      if (!isFirstClass) {
+        finalClasses += ' ';
+      } else {
+        isFirstClass = false;
+      }
+      finalClasses += trimmedClass;
     }
+  }
 
-    if (isString(arg)) {
-      return [arg];
+  return finalClasses;
+}
+
+function processArg(arg: ClassValue, classes: string[]): void {
+  if (arg === undefined || arg === null || arg === false) {
+    return;
+  }
+
+  if (Array.isArray(arg)) {
+    for (let i = 0; i < arg.length; i++) {
+      processArg(arg[i], classes);
     }
+    return;
+  }
 
-    return [];
-  };
+  if (typeof arg === 'object') {
+    for (const key in arg) {
+      if (Object.prototype.hasOwnProperty.call(arg, key)) {
+        const value = arg[key];
+        if (value === true || value === 'true' || value === '1') {
+          classes.push(key);
+        }
+      }
+    }
+    return;
+  }
 
-  return args
-    .flatMap(processArg)
-    .filter(Boolean)
-    .join(" ");
+  if (typeof arg === 'string' || typeof arg === 'boolean') {
+    classes.push(arg.toString());
+  }
 }
diff --git a/src/index.ts b/src/index.ts
index db81aa4..63e7b3f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1 +1 @@
-export {classNames, ClassValue, ClassMap} from "./classnames"
+export {classNames, ClassValue, ClassMap, ClassValueArray} from "./classnames"
diff --git a/tsconfig.json b/tsconfig.json
index 199c89f..c6ccf65 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -8,7 +8,7 @@
     "removeComments": true,
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
-    "target": "ES2021",
+    "target": "es5",
     "outDir": "./dist",
     "skipLibCheck": false,
     "strictNullChecks": false,