数组api
var arr = ['one','two','three'];
arr.forEach(function(val,index){
console.log(val) //one,two,three
console.log(index) //0,1,2
});
- every 用来判断所有的数组元素，都满足一个条件
var resule = arr.every(function(val,index){
if(index < 1 ){
return true;
}
});
console.log(resule) //false
- some 用来判断所有的数组元素，只要有一个满足条件即可
var resule1 = arr.some(function(val,index){
if(index >= 1){
return true;
}
})
console.log(resule1) //true
var arr1 = [1,3,2,10,5];
var resule2 = arr1.sort(function(a,b){
return a -b //从小到大排序
// return b -a 从大到小排序
});
console.log(resule2);//[1,2,3,5,10]
var resule3 = arr.map(function(val,index){
return '<b>'+ val+'</b>'
});
console.log(resule3);//['<b>one</b>','<b>two</b>','<b>three</b>']
var resule4 = arr.filter(function(val,index){
if(val === 'two'){
return true;
}
});
console.log(resule4); //["two"]
