ES6 字符串String 方法 charAt()

var str = new String("This is string");
console.log("str.charAt(0) is:" + str.charAt(0));
console.log("str.charAt(1) is:" + str.charAt(1));
console.log("str.charAt(2) is:" + str.charAt(2));
console.log("str.charAt(3) is:" + str.charAt(3));
console.log("str.charAt(4) is:" + str.charAt(4));
console.log("str.charAt(5) is:" + str.charAt(5));