JAVA

check if string is null or empty java

if(str != null && !str.isEmpty()) { /* do your stuffs here */ }

how to check null and empty string in java

if(str != null && !str.isEmpty())
Be sure to use the parts of && in this order, because java will not proceed to evaluate the second part if the first part of && fails, thus ensuring you will not get a null pointer exception from str.isEmpty() if str is null.

check if a string is empty java

if (myString == null || myString.equals(""))
			throw new IllegalArgumentException("empty string");

check if string is empty

let str1 = "Hello world!";
let str2 = "";
let str3 = 4;
console.log(str1.length === 0)
console.log(str2.length === 0)
console.log(str3.length === 0)

false
true
false

better way to check string on null and empty java

/* You can use Apache Commons  */
StringUtils.isEmpty(str)
  
/* which checks for empty strings and handles null gracefully. */
  
/*   HINT   */  
/* the shorter and simler your code, the easier it is to test it */