Check If String Contains Uppercase Javascript Code Example

Example 1: check if letter is uppercase javascript

const isUpperCase = (string) => /^[A-Z]*$/.test(string)

Example 2: regex for lowercase letters js

function hasLowerCase(str) {     return (/[a-z]/.test(str)); }

Example 3: check if letter is uppercase javascript

isUpperCase('A') // true isUpperCase('a') // false

Example 4: check if letter is uppercase javascript

var strings = 'this iS a TeSt 523 Now!'; var i=0; var character=''; while (i <= strings.length){     character = strings.charAt(i);     if (!isNaN(character * 1)){         alert('character is numeric');     }else{         if (character == character.toUpperCase()) {             alert ('upper case true');         }         if (character == character.toLowerCase()){             alert ('lower case true');         }     }     i++; }