JS-字符串处理

toString() : 在处理数字的时候，接受一个进制参数，默认十进制

    var age = 11;
    var ageAsString = age.toString();    //the string "11"
    var found = true;
    var foundAsString = found.toString(); //the string "true"

// 对数字的处理，可以特殊一点
    var num = 10;
    alert(num.toString());       //"10" 
    alert(num.toString(2));      //"1010"
    alert(num.toString(8));      //"12"
    alert(num.toString(10));     //"10"
    alert(num.toString(16));     //"a"

fromCharCode(); // 把asiic 对应的数字转换为字符串

    alert(String.fromCharCode(104, 101, 108, 108, 111)); //"hello"

indexOf() 与 lastIndexOf() 可以参考数组的用法

slice()、substring()、substr() 截取字符串

    var stringValue = "hello world";
    alert(stringValue.slice(3));        //"lo world"
    alert(stringValue.substring(3));    //"lo world"
    alert(stringValue.substr(3));       //"lo world"
    alert(stringValue.slice(3, 7));     //"lo w"
    alert(stringValue.substring(3,7));  //"lo w"
    alert(stringValue.substr(3, 7));    //"lo worl"

    alert(stringValue.slice(-3));         //"rld"
    alert(stringValue.substring(-3));     //"hello world"
    alert(stringValue.substr(-3));        //"rld"
    alert(stringValue.slice(3, -4));      //"lo w"
    alert(stringValue.substring(3, -4));  //"hel"
    alert(stringValue.substr(3, -4));     //"" (empty string)

String 强制转换

    var value1 = 10;
    var value2 = true;
    var value3 = null;
    var value4;

    alert(String(value1));     //"10"
    alert(String(value2));     //"true"
    alert(String(value3));     //"null"
    alert(String(value4));     //"undefined"

转换大小写

    var stringValue = "hello world";
    alert(stringValue.toLocaleUpperCase());  //"HELLO WORLD"
    alert(stringValue.toUpperCase());        //"HELLO WORLD"
    alert(stringValue.toLocaleLowerCase());  //"hello world"
    alert(stringValue.toLowerCase());        //"hello world"

声明方法的不同，导致类型不同

    var stringObject = new String("hello world");
    var stringValue = "hello world";
    console.log(typeof stringObject);   //"object"
    console.log(typeof stringValue);    //"string"
    console.log(stringObject instanceof String);  //true
    console.log(stringValue instanceof String);   //false

字符串的正则操作：match()、search()、replace()、split()