javascript 下常用的字符串操作

var str = "abac_dfra_wa";
console.log(str.charAt(3)); //输出 c

var str = "abac_dfra_wa";
console.log(str.charCodeAt(3)); //输出99

console.log(String.fromCharCode(72,69,76,76,79)); //输出HELLO

var str = "abac_dfra_wa";
console.log(str.concat('_000')); //输出abac_dfra_wa_000

var str = "abac_dfra_wa"; 
console.log(str.indexOf('ac')); //输出2

var str = "abac_dfra_wa";
console.log(str.lastIndexOf('ac')); //输出2

var str="1 plus 2 equal 3"
console.log(str.match('plus')); // plus
console.log(str.match('st'));   // null
console.log(str.match(/\d+/g))  // [ '1', '2', '3' ]

var str="Hello WoRlD!"
console.log(str.replace(/WoRlD/, "World"));     // Hello World!
var str="Hello WoRlD! "
str += str;
console.log(str.replace(/WoRlD/g, "World")); //替换所有, 输出：Hello World! Hello World! 
var str = "javascript Tutorial ";
console.log(str.replace(/javascript/i, "JavaScript")); //确保匹配字符串大写字符的正确
var name = "Doe, John";
console.log(name.replace(/(\w+)\s*, \s*(\w+)/, "$2 $1")); //将把 "Doe, John" 转换为 "John Doe" 的形式

var str="Hello World!"
console.log(str.search(/World/)); //输出6
var str="Hello World!"
console.log(str.search(/world/i)); //忽略大小写的检索，输出6

var str="Hello happy world!"
console.log(str.slice(6)); //输出happy world!
console.log(str.slice(6, 11)); //输出happy

"|a|b|c".split("|") ////将返回["", "a", "b", "c"]
"How are you doing today?".split(" ",3) //返回 How,are,you
"hello".split("")	//可返回 ["h", "e", "l", "l", "o"]