TS -- for of循环
2017-10-24 本文已影响0人
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# 1 : forEach --- 循环val值 --- 不可break
var arr = ['a','b','c','d'];
arr.desc = "five";//这里在ts会报错
arr.forEach((val,key) => console.log(val,key)); //a 0 b 1 c 2 d 3
# 2 :for in --- 循环key键 --- 不忽略属性
var arr = ['a','b','c','d'];
arr.desc = "five";
for( var key in arr){
console.log( key ); // 0,1,2,3,desc --- key
}
var arr = ['a','b','c','d'];
arr.desc = "five";
for( var key in arr){
console.log( arr[key] ); // a,b,c,d,five --- val
}
# 3：for of --- 循环val值 --- 忽略属性 --- 可break
var arr = ['a','b','c','d'];
arr.desc = "five";
for (var val of arr) {
console.log(val); // a b c d
}
var arr = [1,2,3,4];
for (var val of arr) {
if(val>2) break
console.log(n); // 1 2
}
