var capitalizeMe = "string not starting with capital"

资本化与substr

var capitalized = capitalizeMe.substr(0, 1).toUpperCase() + capitalizeMe.substr(1);

带有箭功能

let fLCapital = s => s.replace(/./, c => c.toUpperCase())
fLCapital('this is a test') // "This is a test"

用火箭功能,另一种解决方案

let fLCapital = s => s = s.charAt(0).toUpperCase() + s.slice(1);
fLCapital('this is a test') // "This is a test"

与 Array 和 地图()

let namesCapital = names => names.map(name => name.replace(/./, c => c.toUpperCase()))
namesCapital(['james', 'robert', 'mary']) // ["James", "Robert", "Mary"]

这样做的一个简单的方式是:

如果您想将其添加到 String.prototype:

使用:

var str = “ruby java”; console.log(str.charAt(0).toUpperCase() + str.substring(1));

它将输出“Ruby java”到控制台。

資本化和無資本化第一條線。

功能包括:

/** First Character uppercase */
function capitalize(str) {
    return str.charAt(0).toUpperCase() + str.slice(1);
}

/** First Character lowercase */
function uncapitalize(str) {
    return str.charAt(0).toLowerCase() + str.slice(1);
}

例1“第一个字符上方”:

alert(capitalize("hello world"));

标签:Hello World

示例2“第一字符下载案例”:

alert(uncapitalize("Hello World, today is sunny"));

此分類上一篇: Hello World, Today Is Sunny

var a = "this is a test"
console.log(a.replace(/^[a-z]/g, txt => txt.toUpperCase()));