check if first letter is uppercase javascript code example
Example 1: javascript capitalize words
//capitalize only the first letter of the string.
function capitalizeFirstLetter(string) {
return string.charAt(0).toUpperCase() + string.slice(1);
}
//capitalize all words of a string.
function capitalizeWords(string) {
return string.replace(/(?:^|\s)\S/g, function(a) { return a.toUpperCase(); });
};
Example 2: 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 3: js first letter to uppercase
function capitalizeFirstLetter(name) {
return name.replace(/^./, name[0].toUpperCase())
}
Example 4: how to check if the first letter of a string is capitalized or uppercase in js
function startsWithCapital(word){
return word.charAt(0) === word.charAt(0).toUpperCase()
}
console.log(startsWithCapital("Hello")) // true
console.log(startsWithCapital("hello")) // false