string contains some special character literal, also called escape sequence, \ n meaning is newline, \ t meaning for the tabulation, \b meaning space, \ r Enter, \ \ Slash.
The string in 1.ECMAScript is immutable.
2. Method of Converting a string: ToString () returns the string pattern of the corresponding value. Null and undefined no this method, others have.
3. If you do not know if the value to be converted is null or undefined, you can use the Transform function string (), which converts any value to a string.
Alert (String (value1)); "NULL"
Alert (String (value2)); "Undefined"
The string data type in JS