function getAttackString() {
var foo = "d322yvb34";
var bar = "x3nj4nhj9";
return "The code is: "+(foo.substr(3,foo.length-6))+(bar.substr(2);
}
我不知道“+(foo.substr(3,foo.length-6))+(bar.substr(2)”的含义是什么。
答案 0 :(得分:1)
从字符串索引3
开始,从foo.length-6
获取foo
个字符(3
)的子字符串:
foo.substr(3,foo.length-6)
这将从字符串索引bar
开始获取2
中所有字符的子字符串:
bar.substr(2)
然后连接起来。
您发布的代码有一个小错字。这是工作代码。
function getAttackString() {
var foo = "d322yvb34";
var bar = "x3nj4nhj9";
return "The code is: " + (foo.substr(3, foo.length - 6)) + bar.substr(2);
}
console.log(getAttackString())
答案 1 :(得分:0)
您可以查看String#substr
的参数str.substr(start[, length])
考虑到这一点,您可以完成所有部分并通过单个部分进行手动操作:
indices 012345678 action
string d322yvb34
foo.substr(3, foo.length - 6)
2yv foo.substr(3, 9 - 6)
indices 012345678
string x3nj4nhj9
nj4nhj9 bar.substr(2)
result 2yv nj4nhj9
获得结果
2yvnj4nhj9
答案 2 :(得分:0)
以下是您的完整代码说明。
// getAttackString is a function and the function name is "getAttackString"
function getAttackString() {
var foo = "d322yvb34";
var bar = "x3nj4nhj9";
//The substr() method extracts parts of a string, beginning at the character
//at the specified position, and returns the specified number of characters.
return "The code is: " + (foo.substr(3, foo.length - 6)) + bar.substr(2);
//Lets see what is going on here...
// 012345678
//foo = "d322yvb34"
//(foo.substr(3, foo.length - 6)) + bar.substr(2);
//Start from 3rd char (this means start at "2yvb34"),
//End at (foo.length - 6) i.e 9-6 = 3 = "2yv"
//Add bar.substr(2) bar = x3nj4nhj9
//Start from 2 i.e = "nj4nhj9"
//Now add "2yv" + "nj4nhj9" = "2yvnj4nhj9"
}
console.log(getAttackString())