javascript check if string contains uppercase character code example
Example 1: javascript check if all capital letter
function isUpper(str) {
return !/[a-z]/.test(str) && /[A-Z]/.test(str);
}
isUpper("FOO"); //true
isUpper("bar"); //false
isUpper("123"); //false
isUpper("123a"); //false
isUpper("123A"); //true
isUpper("A123"); //true
isUpper(""); //false
Example 2: check if letter is uppercase javascript
isUpperCase('A') // true
isUpperCase('a') // false