To pass props as initial data in Vue.js, we can set the prop value as an initial value of a reactive property.
For instance, we write
<script>
export default {
//...
props: {
record: {
type: Object,
required: true,
},
},
data() {
return {
recordLocal: { ...this.record },
};
},
//...
};
</script>
to set the recordLocal reactive property to a copy of the record prop as its initial value.
We register the record prop in the props property.
To add the equivalent of the PHP strcmp() function with JavaScript, we can use the string localeCompare method.
For instance, we write
str1.localeCompare(str2)
to compare the values of str1 and str2 by their lexical order.
It’s aware of the locale the device is using when doing the comparison.
To do method overloading in TypeScript, we can add multiple signatures for the same method.
For instance, we write
class TestClass {
someMethod(stringParameter: string): void;
someMethod(numberParameter: number, stringParameter: string): void;
someMethod(stringOrNumberParameter: any, stringParameter?: string): void {
if (stringOrNumberParameter && typeof stringOrNumberParameter == "number") {
//...
} else {
//...
}
}
}
to add the someMethod in TestClass that has multiple signatures.
We specify all the possible signatures for the method by adding the parameters and their types for each one.
And then we check the values of the parameters with if statements before we do anything with them.
To add dictionaries in JavaScript like Python, we can create an object.
For instance, we write
const statesDictionary = {
CT: ["alex", "harry"],
AK: ["liza", "alex"],
TX: ["fred", "harry"],
};
console.log(statesDictionary.AK[0]);
to create the statesDictionary object that has some keys and values inside.
Then we can access the object’s property values by writing
statesDictionary.AK[0]
To check if a string has white space with JavaScript, we can use the regex test method.
For instance, we write
const hasWhiteSpace = (s) => {
return /\s/g.test(s);
};
to define the hasWhiteSpace function that checks if string s has any whitespaces with /\s/g.test.
We use \s to match any whitespaces in s.
The g flag makes test check for all instances of whitespaces.
To check if a string has white space with JavaScript, we can use the regex test method.