javascript给String类和Array扩展常用方法

/*
String类: first、last、has、has_any、has_all、is_in、format
Array类: first、last、has、has_any、has_all、is_in、any_in、all_in
*/
var has_any = function() {
var list = arguments;
if (typeof(list[0])=='object') {
list = list[0];
}
var result = false;
for (var i=0; i<list.length; i++) {
if (this.has(list[i])) {
result = true;
break;
}
}
return result;
}
var has_all = function() {
var list = arguments;
if (typeof(list[0])=='object') {
list = list[0];
}
var result = true;
for (var i=0; i<list.length; i++) {
if (!this.has(list[i])) {
result = false;
break;
}
}
return result;
}

/*** String类 ***/
String.prototype.format = function() {
var args = arguments;
return this.replace(/\{(\d+)\}/g,
function(m,i) {
return args[i];
}
)
}

String.prototype.first = function(len) {
var len = len || 1;
return this.substr(0, len);
}

String.prototype.last = function(len) {
var len = len || 1;
return this.substr(-len ,len);
}

String.prototype.has = function(obj) {
return this.indexOf(obj.toString())>-1;
}

String.prototype.has_any = has_any;
String.prototype.has_all = has_all;

String.prototype.is_in = function(container) {
return container.has(this);
}

/*** Array类 ***/
Array.prototype.first = function(len) {
if (len) {
return this.slice(0, len);
} else {
return this[0];
}
};

Array.prototype.last = function(len) {
if (len) {
return this.slice(-len, this.length);
} else {
return this.reverse()[0];
}
};

Array.prototype.has = function(obj) {
var result = false;
for (var i=0; i<this.length; i++) {
if (this[i]==obj) {
result = true;
break;
}
}
return result;
}

Array.prototype.has_any = has_any;
Array.prototype.has_all = has_all;

Array.prototype.is_in = function(container) {
return container.has(this);
}

Array.prototype.any_in = function(container) {
return container.has_any(this);
};

Array.prototype.all_in = function(container) {
return container.has_all(this);
};