function keepAlphanumeric keepAlphanumeric(text: string): string Returns a copy of the given string with all non-alphanumeric characters removed, except for spaces. Letters and digits are preserved regardless of case. Examples Example 1 keepAlphanumeric(null); // "" keepAlphanumeric("Hello, World!"); // "Hello World" keepAlphanumeric("123@#Test"); // "123Test" Parameters text: string Return Type string