循環方法 | 說明 |
---|---|
forEach | 不可終止循環 |
some | 返回true終止循環 |
findIndex | 返回true可以終止循環,返回滿足條件的索引 |
filter | 返回過濾後的數組 |
- forEach
var list = [
{
id:1,
userName:'王小小',
age:24,
},
{
id:2,
userName:'李四',
age:14,
},
{
id:3,
userName:'張三',
age:33,
}
]
list.forEach((item,i)=>{
console.log('id:'+item.id+';'+'姓名:'+item.userName+';'+'年齡:'+item.age)
})
打印結果
id:1;姓名:王小小;年齡:24
id:2;姓名:李四;年齡:14
id:3;姓名:張三;年齡:33
- some
var list = [
{
id:1,
userName:'王小小',
age:24,
},
{
id:2,
userName:'李四',
age:14,
},
{
id:3,
userName:'張三',
age:33,
}
]
list.some((item,i)=>{
if(item.id ===2) {
console.log('id:'+item.id+';'+'姓名:'+item.userName+';'+'年齡:'+item.age)
//返回true 終止循環
return true
}
})
打印結果
id:2;姓名:李四;年齡:14
true
- findIndex
var list = [
{
id:1,
userName:'王小小',
age:24,
},
{
id:2,
userName:'李四',
age:14,
},
{
id:3,
userName:'張三',
age:33,
}
]
var index=list.findIndex(item=>{
if(item.id ===2) {
return true
}
})
console.log(index)
打印結果
1
- filter
var list = [
{
id:1,
userName:'王小小',
age:24,
},
{
id:2,
userName:'李四',
age:14,
},
{
id:3,
userName:'張三',
age:33,
}
]
var arr=list.filter(item=>{
return item.age>18
})
console.log(arr)
打印結果
[{id:1,userName:'王小小',age:24,},{id:3,userName:'張三',age:33,}]